Cement additive, method for producing the same, and cement composition

ABSTRACT

A cement additive composed of a crosslinked polymer in which, between main chains having a water-soluble polymer structure of a molecular weight from 500 to 100,000, there is a bond having as a structural unit at least one divalent group having the following formula (I): ##STR1## where R 1  and R 2  independently denote any one of the following: ##STR2## where R 1  is not required, if R 2  is the following: ##STR3## and where R and R&#39; independently denote an alkyl group of carbon number of 1 to 5.

TECHNICAL FIELD

The present invention relates to a cement additive having an ability toprevent slump loss. More particularly, the invention relates to achemical which is combined with a cement composition such as cementmortar and concrete etc. and elevates efficiency in the workability byincreasing the flowability of the cement composition and its decreasewith time passage (hereinafter, referred to as the "slump loss") isprevented. The present invention also relates to a method for producingsuch a cement additive. Furthermore, the present invention relates to acement composition which is combined with a cement additive of the abovekind.

BACKGROUND ART

A cement composition such as mortar and concrete etc. shows a decreasein consistency with passage of time after combination by the hydrationof cement with water or others and thereby, the efficiency in theexecution of works lowers. This phenomenon is generally called slumploss.

The slump loss in the cement composition causes, on ready mixedconcrete, trouble such as limitation of time allowed for transportation,degeneration of quality and impairment of workability owing to a waitingtime in a concrete-placing field, and a decrease in durability due to acold joint and so on. Also, in a factory for producing concretesecondary products, when transportation of a cement composition by apump pressure is temporarily stopped by taking a lunch time or due toany trouble and, some times later, the transportation by pressure isreopened, the slump loss may cause such an accident as a sudden increasein the transportation pressure or full closure of a pump and may causesuch a problem as incomplete filling in a delaying case of moulding suchas compaction for some reason. Therefore, in the factories for producingready-mixed concrete and for producing concrete secondary products andin the other places, the slump loss in a cement composition is animportant problem to be solved in order to control the quality of cementcompositions and to improve the efficiency in the execution of work.

The following methods to prevent the slump loss have been proposed.

(1) A method in which an unit amount of water in concrete is increased.

(2) A method which comprises a post-addition of a cement additive.

(3) A method which comprises a repetitive addition of a cement additive.

(4) A method which comprises an addition of a retarder or a combined usewith a cement additive.

(5) A method in which a cement additive of a granular type is used.

(6) A method in which a cement additive is contained in an organichydrogel.

(7) A method which comprises an addition of a cement additive thatundergoes slow-release of a dispersing effect for cement resulting fromslow hydrolysis by an alkali.

Said method (1) comprises an increase of an unit amount of water whichis estimated with the slump loss up to placing of a cement composition.Even if an improvement in the workability is attempted by this method,the method may be accompanied by such a disadvantage in quality as aloss of strength of a hardened product and crack occurrence resultingfrom shrinkage during drying, which causes a decrease in durability orsuch an economic disadvantage as an increase in an unit amount of cementwhich is required to obtain a defined strength.

Said method (2) is a temporary improvement for a flowability. However,the cement additive remains locally in the cement composition after anattempt to maintain the slump has been completed and, as a result, therewill be brought a bad effect such as occurrence of local bleeding andthereby, a loss of strength.

Said method (3) comprises a readdition of an additive when the slumploss occurs. However and it is not a complete prevention for the slumploss. Also, there is a disadvantage in the workability and economy dueto the repetitive addition.

Said method (4) seeks to maintain flowability by lengthening the timenecessary for coagulation of a cement composition by using only adelaying agent such as a hydroxycarboxylate, a ligninsulfonate, adextrin, and a humic acid etc. or by using those in combination with acement additive and, therefore, in a case of an excess addition there isa danger of accidents such as a loss of strength and inferior setting.

The method (5) is the one in which a condensation product ofnaphthalenesulfonic acid with formalin is granulated and graduallydissolved in a cement composition to prevent the slump loss (JapaneseOfficial Patent Provisional Publication, showa 54-139929) or the one inwhich a copolymer of an olefin with an ethylenic unsaturateddicarboxylic acid anhydride gradually undergoes hydrolysis in a cementcomposition to prevent the slump loss (Japanese Official PatentProvisional Publications, showa 60-16851 and heisei 1-122947). But inboth these methods, the granular additive is dispersed in solution, themethods involve localization of the additive and a problem a storagestability. Furthermore, to prevent said localization of an additive andthe problem of storage stability, there has been proposed a method inwhich a finely granulated cement additive is obtained by that a solutionbeing dispersed with a copolymer of a vinylic compound with an ethylenicunsaturated dicarboxylic acid anhydride is stirred with a rigid bodymedia (Japanese Official Patent Provisional Publication, showa62-241855), but this method requires a device such as a sand mill forstirring, so that the production process becomes complex.

The method (6) is the one in which a cement-dispersing agent iscontained in such an organic water-containing gel as polyacrylic acidetc. and it gradually releases in the cement paste (Japanese OfficialPatent Provisional Publication, showa 63-162562), but because itinvolves a gel which is not dissolved in water, there is a problem ofstorage stability such as separation and precipitation etc.

The method (7) comprises a method in which as a cement additive, apoly(meth)acrylic acid ester is used in combination with such acement-dispersing agent as sodium ligninsulfonate, sodiummelaminesulfonate, and sodium polyacrylate (Japanese Official PatentProvisional Publication, showa 60-161365), and a method in whichdispersion of cement particles is in tended by using methylpoly(meth)acrylate or a copolymer of t-butyl maleate with isobutylene[A. Ohta, Y. Tanaka, and T. Uryu: Polymer Preprints, Japan Volume 38,No. 3 (1989)]. In the polymers which are used as cement additives of theforementioned kinds, the carboxyl groups directly binding to a carbonatom of the main chain are all esterified. Because of this, when thepolymers are combined with a cement composition, they are hardlycompatible with water and the cement composition becomes non-uniform andthe setting inferiority etc. often takes place due to local existence ofthe additive.

In short, all the methods have their own defects and there has not beenfound any satisfactory cement additive.

Thus, the first object of the present invention is to provide a cementadditive which, by being added to a cement composition, is able toimprove said defects, enhance its flowability, and prevent the slumploss. The second object of the present invention is to provide a methodfor producing such a superior cement additive as forementioned and also,with which a molecular structural design is easy. The third object ofthe present invention is to provide a production method which canproduce such a superior cement additive as forementioned by taking onlya short process. Furthermore, the fourth object of the present inventionis to provide a cement composition in which said superior cementadditive is combined.

DISCLOSURE OF INVENTION

The present inventors have considered, in order to improve the defectsin said methods of (1) to (4), that the use of a cement additive whichgradually displays a dispersing effect on the cement in a cementcomposition is essential, and thus we carried out examination of thecement additive. However, since the cement additive in said method (5)uses a phenomenon of that a solid gradually dissolves into an aqueoussolution, and since the cement additive in said method (6) contains acement-dispersing agent in an organic water-containing gel, there hasoccurred such a problem as the additive exists locally, as theforementioned. In the cement additive of said method (7), the carboxylgroups directly binding with a main chain of the polymer are allesterified, so that a problem of the above kind also takes place.

On the other hand, if a cement additive takes the form of an aqueoussolution or dispersion by being mixed beforehand with a part of waterfor mixing and kneading, there is an advantage that its handling may bevery easy, but such a form in use may be not possible in the case of asolid which does not dissolve in ordinary water or in the case of acement additive composed of a hydrogel. Among the hitherto-used cementadditives which described above, a cement additive of which thedissolving proceeds with hydrolysis may be preserved in mixing withordinary water, but such a problem takes place that storage stabilityare inferior because a dispersing state in water is not maintained andthe additive precipitates.

Therefore, the present inventors considered that, if the dispersingeffect with conversion of a polymer into a compound of low molecularweight is arranged, such a problem of that a cement additive existslocally in a cement composition or the storage stability in water isinferior may be solved. Thus, we carried out examination of suchpolymers. As a result, we found that a crosslinked polymer containing adefined crosslinking chain is effective, and we attained the presentinvention.

Accordingly, to achieve said first object, the present inventionprovides a cement additive composed of a crosslinked polymer in which,between the main chains having a water-soluble polymer structure of amolecular weight of 500 to 100,000, a bond having as a structural unitat least one group selected from the divalent groups as shown in thefollowing formula (I) is formed. ##STR4## [In the formula (I), R¹ and R²independently denote any one of ##STR5## However, R¹ may be none if R²is ##STR6## Moreover, R and R' independently denote an alkyl group ofcarbon number of 1 to 5.]

Said main chain has, for example, at least one kind selected from thefunctional groups of the undermentioned 1 to 5. ##STR7## [Here, m is 0or an integral number of 1 to 50; n is 0 or 1; M is any one of ahydrogen atom or a monovalent, divalent, or trivalent metal, or anammonium group or an organic amine group; R⁵ and R⁶ independently denotean alkylene group of carbon number of 2 to 4; R⁷ denotes an alkylenegroup of carbon number of 1 to 5. Moreover, when m is 2 or more, aplural R⁵ O all do not need to be an identical group and, when a pluralR⁵ O are one another a different group, their arrangement may be regularor irregular.]

Also, said main chain has, for example, at least one kind of functionalgroup selected from the functional groups of said 1 to 5 and at leastone kind of functional group selected from the functional groups of said6 to ○ 12 as well. ##STR8## [Here, p is an integral number of 1 to 10; qis 0 or an integral number of 1 to 100; r and s are, respectively, anintegral number of 1 to 3; t and u are, respectively, an integral numberof 1 to 100; A¹ is a divalent or trivalent ring-opened group of analkyleneimine of carbon number of 2 to 4 (in a case of the divalent, A¹is a straight chain type and, in a case of the trivalent, it is abranched type); R⁵ is an alkylene group of carbon number of 2 to 4; R⁸is CH₃ or C₂ H₅ ; R⁹ is H, CH₃, or C₂ H₅ ; R¹⁰ is H or an alkyl group ofcarbon number of 1 to 5; and X.sup.⊖ is an anionic pair ion. Besides,when p is two or more, a plural A¹ all do not need to be an identicalgroup and, when a plural A¹ are one another a different group, theirarrangement may be regular or irregular. When q is not 0, thearrangement of A¹ and R⁵ O may be normal or reverse and may be regularor irregular. When q is 2 or more, when t is 2 or more, and when u is 2or more, respectively, a plural R⁵ O all do not need to be an identicalgroup and, when a plural R⁵ O are one another a different group, theirarrangement may be regular or irregular. When a group being representedby the same symbol in a formula is contained in two or more, all thegroups do not need to be an identical group.]

To achieve said second object, the present invention also provides amethod for producing a cement additive, wherein water-soluble polymershaving a molecular weight of 500 to 100,000 are one another combined byusing a crosslinking agent which has as a structural unit at least onegroup selected from the divalent groups being represented by saidformula (I) and/or is capable of forming such a group to obtain acrosslinked polymer.

Said water-soluble polymer has, for example, at least one kind selectedfrom the functional groups of the above-mentioned 1 to 5, or has atleast one kind selected from the functional groups of theabove-mentioned 1 to 5 and at least one kind selected from thefunctional groups of the above-mentioned 6 to ○ 12 .

To achieve said third object, the present invention further provides amethod for producing a cement additive, wherein obtains a crosslinkedpolymer by that a monomer (e), which has two or more of polymerizabledouble bonds and, between each of these polymerizable double bonds, hasas a structural unit at least one kind of group selected from thedivalent groups being represented by said formula (I), is polymerizedwith a monomer (f), which has one polymerizable double bond capable ofcopolymerizing with the monomer (e) and is possible to form a main chainstructure capable of making a water-soluble polymer having a molecularweight of 500 to 100,000.

To achieve said fourth object, the present invention provides a cementcomposition, of which essential components are a cement additivecomposed of said specially defined crosslinked polymer, cement, andwater. Also, it provides a cement composition in which a cement additiveobtained by said specified method, cement and water are essentialcomponents.

The crosslinked polymer used in the present invention has a structure inwhich main chains of two or more are crosslinked with one another. Saidmain chains are composed of carbon-carbon bonds only or has a structurein which the bonds are a main body. The main chains convert into awater-soluble polymer having an ability capable of dispersing cement, bythat the crosslinking chains are cleaved. Moreover, here thecrosslinking chain means a divalent group being represented by saidformula (I) (this is a case that only one divalent group is contained)and, in a case of that two or more of the divalent group beingrepresented by said formula (I) is contained, the crosslinking chainmeans a structure between each of the divalent groups located at theseparated, furthest positions.

Said crosslinking bond is a bond having at least one group selected fromthe divalent groups being represented by said formula (I). Although thisbond has an ester bond, its position is important. That is, either theester bond locates at a position separated from a main chain carbon atomat least by one carbon atom, or in a case of that the ester bond isdirectly bound to a main chain carbon atom, in a structure beingrepresented by said formula (I) R² is following: ##STR9## The bond ofthis kind is cited, for example, as following three kinds, but is notlimited within the kinds. ##STR10## [wherein R²⁰ denotes, for example, adivalent group modified from alkylene oxide.] ##STR11## [wherein R²¹denotes, for example, alkylene group. Moreover, when a number of R²¹ is2 or more, all the R²¹ do not need to be an identical group.]

A cement-dispersing ability and solubility in water of saidwater-soluble polymer are provided by at least one functional group inthe functional groups of said 1 to 5 being involved in said main chain,or provided by at least one functional group in the functional groups ofsaid 1 to 5 and at least one group in the functional groups of said 6 to○ 12 . In the functional groups of said 1 to 5, M is anyone of ahydrogen atom, mono-, di-, or trivalent metal, an ammonium group, or anorganic amine group. The monovalent metal is, for example, sodium andpotassium. The divalent metal is, for example, magnesium, calcium, andbarium. The trivalent metal is, for example, aluminum. The organic aminegroup is, for example, trimethylamine, triethylamine, andtriethanolamine.

Said water-soluble polymer has an average molecular weight of 500 to100,000 and, preferably, an average molecular weight of a range from3,000 to 50,000, more preferably, an average molecular weight of a rangefrom 5,000 to 30,000. A water-soluble polymer of this kind iscrosslinked to another such polymer by said specially defined bond toform a crosslinked polymer. A crosslinking agent used for forming acrosslinked polymer is preferred to have, for example, an averagemolecular weight of a range from 100 to 5,000, more preferably, it hasan average molecular weight of 1,000 or less. Also, the monomer (e) ispreferred to have, for example, an average molecular weight of a rangefrom 200 to 5,000. Besides, the water-soluble polymer need not have amolecular weight larger than that of the crosslinking agent. If themolecular weight of a water-soluble polymer deviates from said range,the dispersing character may be inferior or the air amount mayabnormally increase. Because of this, said crosslinked polymer is veryhydrophilic and, in a preferable case, shows solubility in water.

Said water-soluble polymer is, for example, at least one kind ofcompound selected from a homopolymer and a copolymer which is led byusing at least one kind of monomer selected from the monomers of theundermentioned (i) to (vi), and selected from the addition reactionproducts having at least either one of the structural units in said theundermentioned (vii) and (viii), which are led from an addition reactionof the group (--COOM) being involved in the above polymers with at leastalkyleneimine in a group of an alkyleneimine and an alkylene oxide.##STR12## [Here, m is 0 or an integral number of 1 to 50; n is 0 or 1; pis an integral number of 1 to 10; q is 0 or an integral number of 1 to100; M is any one of a hydrogen atom or a monovalent, divalent, ortrivalent metal group, or an ammonium group or an organic amine group;R³ and R⁴ independently are H or CH₃ ; R⁵ and R⁶ independently representan alkylene group of carbon number of 2 to 4; R⁷ represents an alkylenegroup of carbon number of 1 to 5; and A¹ is a divalent or trivalentring-opened group of carbon number of 2 to 4 (it is a straight chaintype in a case of the divalent and a branched type in a case of thetrivalent). Moreover, when m is 2 or more and when q is 2 or more,respectively, a plural R⁵ O all do not need to be an identical groupand, when a plural R⁵ O are one another a different group, theirarrangement may be regular or irregular. When p is 2 or more, a pluralA¹ all do not need to be an identical group and, when a plural A¹ areone another a different group, their arrangement may be regular orirregular. When q is not 0, the arrangement of A¹ and R⁵ O may be normalor reverse and may be regular or irregular. When a group or number beingrepresented by an identical symbol in one formula is 2 or more, thegroup or number all do not need to be an identical group or number.]

Said water-soluble polymer is at least one kind of compound, forexample, selected from a copolymer which is led by using at least onekind of monomer selected from the monomers of the forementioned (i) to(vi) and at least one kind of monomer selected from the monomers of theundermentioned (ix) to (xiv), and selected from the addition reactionproducts having at least either one of the structural units in said theforementioned (vii) and (viii), which are led from an addition reactionof the group (--COOM) being involved in the above copolymers with atleast alkyleneimine in a group of an alkyleneimine and an alkylene oxidewith. ##STR13## [Here, r and s are, respectively, an integral number of1 to 3; t and u are, respectively, an integral number of 1 to 100; R³and R⁴ are, respectively, H or CH₃ ; R⁵ is an alkylene group of carbonnumber of 2 to 4; R⁸ is CH₃ or C₂ H₅ ; R⁹ is H, CH₃, or C₂ H₅ ; R¹⁰ is Hor an alkyl group of carbon number of 1 to 5; and X.sup.⊖ is an anionicpair ion. Besides, when t is 2 or more and when u is 2 or more,respectively, a plural R⁵ O all do not need to be an identical groupand, when a plural R⁵ O are one another a different group, theirarrangement may be regular or irregular. When a group being representedby the same symbol in a formula is contained in two or more, all thegroups do not need to be an identical group.]

In a case that a water-soluble polymer and crosslinked polymer have saidgroups (vii) and/or (viii), such a water-soluble polymer and crosslinkedpolymer are, for example, obtained by the following. To a group (--COOM)which a water-soluble polymer has, at least alkyleneimine in a group ofalkyleneimine and alkyleneoxide is added by means of hitherto knownmethod. The alkyleneimine may be only added, or alkyleneimine andalkyleneoxide may be added together. In a case of the joint addition,they can be simultaneously added to said water-soluble polymer havingthe group (--COOM) to carry out reaction, or the reaction can be carriedout one by one; for example, a reaction of alkyleneimine may be carriedout, and then, alkyleneoxide may be added for reaction. As examples ofthe alkyleneimine of carbon number of 2 to 4 used in the presentinvention, are cited various compounds, for example, ethyleneimine andpropyleneimine etc. are cited as proper examples.

As examples of the monomer (i) used in the present invention are citedacrylic acid and methacrylic acid as well as their monovalent metalsalts, divalent metal salts, trivalent metal salts, ammonium salts, andorganic amine salts, and one kind or two or more kinds of thesecompounds can be used.

As examples of the monomer (ii) used in the present invention are citedmaleic acid and citraconic acid and their anhydrides as well as theirmonovalent metal salts, divalent metal salts, trivalent metal salts,ammonium salts, and organic amine salts, and one kind or two or morekinds of these compounds can be used.

As examples of the monomer (iii) used in the present invention arecited, for example, sulfoalkyl (meth) acrylates such as 2-sulfoethyl(meth)acrylate, 2-sulfopropyl (meth)acrylate, 3-sulfopropyl(meth)acrylate, 1-sulfopropan-2-yl (meth)acrylate, 2-sulfobutyl (meth)acrylate, 3-sulfobutyl (meth)acrylate, 4-sulfobutyl (meth) acrylate,1-sulfobutan-2-yl (meth)acrylate, 1-sulfobutan-3-yl (meth)acrylate,2-sulfobutan-3-yl (meth) acrylate, 2-methyl-2-sulfopropyl(meth)acrylate, 2-methyl-3-sulfopropyl (meth)acrylate, and1,1-dimethyl-2-sulfoethyl (meth)acrylate etc., and their monovalentmetal salts, divalent metal salts, trivalent metal salts, ammoniumsalts, and organic amine salts; sulfoalkoxypolyalkylene glycolmono(meth)acrylate such as sulfoethoxypolyethylene glycolmono(meth)acrylate, sulfopropoxypolyethylene glycol mono(meth)acrylate,sulfobutoxypolyethylene glycol mono(meth)acrylate,sulfethoxypolypropylene glycol mono(meth)acrylate,sulfoproxypolypropylene glycol mono(meth)acrylate, andsulfobutoxypolypropylene glycol mono(meth)acrylate etc., and theirmonovalent metal salts, divalent metal salts, trivalent metal salts,ammonium salts, and organic amine salts. These compounds can be alsoused as one kind or two or more kinds in combination.

As examples of the monomer (iv) used in the present invention are cited,for example, a crylamidomethanesulfonic acid, acrylamidoethanesulfonicacid, acrylamidopropanesulfonic acid,2-acrylamido-2-methylpropanesulfonic acid, methacrylamidomethanesulfonicacid, and methacrylamidoethanesulfonic acid, and their monovalent metalsalts, divalent metal salts, trivalent metal salts, ammonium salts, andorganic amine salts. These compounds can be also used as one kind or twoor more kinds in combination.

As examples of the monomer (v) used in the present invention are cited,for example, ethylenesulfonic acid, allyl sulfonic acid, methallylsulfonic acid, and their monovalent metal salts, divalent metal salts,trivalent metal salts, ammonium salt, organic amine salts. Thesecompounds can be also used as one kind or two or more kinds incombination.

As examples of the monomer (vi) used in the present invention are cited,for example, sulfonic styrene such as p-styrenesulfonic acid etc. andits monovalent metal salts, divalent metal salts, trivalent metal salts,ammonium salt, organic amine salts. These compounds can be also used asone kind or two or more kinds in combination.

As examples of the monomer (ix) used in the present invention are cited,for example, dimethylaminoethyl acrylate, diethylaminoethyl acrylate,dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate, andtheir monovalent metal salts, divalent metal salts, trivalent metalsalts, ammonium salt, organic amine salts. These compounds can be alsoused as one kind or two or more kinds in combination.

As examples of the monomer (x) used in the present invention are cited,for example, the compounds which are obtained from reaction of saidmonomer (ix) with the hitherto known quaternary reagent, for example, analkyl halogenide, an aralkyl halogenide, and a dialkylsulfuric acid etc.These compounds can be also used as one kind or two or more kinds incombination.

As examples of the monomer (xi) used in the present invention are cited,for example, dimethylaminopropylacrylamide,diethylaminopropylacrylamide, dimethylaminopropylmethacrylamide, anddiethylaminopropylmethacrylamide etc. These compounds can be also usedas one kind or two or more kinds in combination.

As examples of the monomer (xii) used in the present invention arecited, for example, the compounds which are obtained from reaction ofsaid monomer (xi) with the hitherto known quaternary reagent, forexample, an alkyl halogenide, an aralkyl halogenide, and adialkylsulfuric acid etc. These compounds can be also used as one kindor two or more kinds in combination.

As examples of the monomer (xiii) are cited, for example, polyalkyleneglycol mono(meth)allyl ether such as polyethylene glycol monoallylether, polypropylene glycol monoallyl ether, polyethyleneglycol-polypropylene glycol monoallyl ether, polyethylene glycolmonomethallyl ether, polypropylene glycol monomethallyl ether,polyethylene glycol-polypropylene glycol monomethallyl ether etc. Thesecompounds can be also used as one kind or two or more kinds incombination.

As examples of the monomer (xiv) are cited, for example, hydroxyethyl(meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropyleneglycol mono(meth) acrylate, polybutylene glycol mono(meth)acrylate,methoxypolyethylene glycol mono(meth)acrylate, methoxypolypropyleneglycol mono(meth)acrylate, methoxypolybutylene glycolmono(meth)acrylate, ethoxypolyethylene glycol mono(meth)acrylate,ethoxypolypropylene glycol mono(meth)acrylate, ethoxypolybutylene glycolmono(meth)acrylate, polyethylene glycol polypropylene glycolmono(meth)acrylate, and polyethylene polytetramethylene glycolmono(meth)acrylate etc. These compounds can be also used as one kind ortwo or more kinds in combination.

In the present invention, as the monomer (f), for example, at least onekind among said monomers from (i) to (vi) can be used, or with this, atleast one kind among said monomers from (ix) to (xiv) can be used incombination.

Although the monomer (e) used in the present invention can be producedby a method known in public or by a combination of the methods inpublic, the representative methods are exemplified as follows.

1 A reaction of at least one of monoester diols and polyester polyolswith a polymerizable monomer having a functional group capable ofreacting with the hydroxyl groups in the above diols and polyols.

2 A reaction of at least one of monoester dicarboxylic acids andpolyester polycarboxylic acids with a polymerizable monomer having afunctional group capable of reacting with the carboxyl groups in theabove acids.

3 A reaction of at least one of polyols and polyepoxy compounds with apolymerizable monomer having a carboxyl group which is apart from apolymerizable double bond by at least one carbon atom.

4 A reaction of polycarboxylic acids with a polymerizable monomer havinga hydroxyl or an epoxy group which is apart from a polymerizable doublebond by at least one carbon atom.

5 A reaction of at least one of monoester polyepoxy compounds andpolyester polyepoxy compounds with a polymerizable monomer having afunctional group capable of reacting with the epoxy groups in the abovecompounds.

As the monoester diols and polyester polyols in the production method 1,are cited reaction products of diol compounds such as ethylene glycol,propylene glycol, diethylene glycol, dipropylene glycol,1,5-pentanediol, 1,6-haxanediol, and neopentylglycol etc., with dibasicacids such as succinic acid, adipic acid, phthalic acid,hexahydrophthalic acid, and tetrahydrophthalic acid etc.; reactionproducts of said dibasic acids with cyclic ethers such as ethylene oxideand propylene oxide etc.; reaction products of said diol compounds withhydroxycarboxylic acids such as glycolic acid, α-hydroxyacrylic acid,salicylic acid, and mandelic acid etc.; reaction products of saidhydroxycarboxylic acids with said cyclic ethers; and reaction productsof said diols or polyalcohols such as pentaerythritol,trimethylolpropane, trimethylolethane, ditrimethylolpropane, anddipentaerythritol etc. with lactones such as β-propiolactone,γ-butyrolactone, δ-valerolactone, and ε-caprolactone etc.

As the polymerizable monomers having a functional group capable ofreacting with a hydroxyl group in the production method 1, are citedacrylic acid, methacrylic acid, maleic acid, glycidyl (meth)acrylate,(meth) acryloylaziridine, (meth)acryloyloxyethylaziridine,2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, isocyanateethyl(meth)acrylate, (meth)acryloyl chloride, and allyl chloride etc.

As the monoester dicarboxylic acids and/or polyester polycarboxylicacids in the production method 2, compounds similar to those exemplifiedin the production method 1 can be used.

As the polymerizable monomers having a functional group capable ofreacting with a carboxylic group in the production method 2, are citedallyl alcohol, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate,(meth)acryloylaziridine, (meth)acryloyloxyethylaziridine,2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline, and isocyanateethyl(meth)acrylate etc.

As the polyols in the production method 3, are cited polycarbonatepolyols, polyether polyols, polybutadiene polyols, and hydrogenatedpolybutadiene polyols etc. in addition to the polyester polyolsexemplified in the production method 1. As the polycarbonate polyols arecited addition compounds of 2 to 6 moles of ethylene oxide withcompounds such as 1,6-hexanediol, neopentylglycol, 1,4-butanediol,1,8-octanediol, 1,4-bis-(hydroxymethyl)-cyclohexane,2-methylpropanediol, dipropylene glycol, dibutylene glycol, andbisphenol A; diols which are reaction products of said diol compoundswith dicarboxylic acids such as oxalic acid, malonic acid, succinicacid, adipic acid, azelaic acid, and hexahydrophthalic acid etc.;polycarbonate polyols which have as a diol component a polyester dioletc. that is an addition reaction product of said diol compound withε-caprolactone or δ-valerolactone; and polycarbonate polyols that areaddition reaction products of polycarbonate polyols of the forementionedkinds with ethylene oxide, propylene oxide, ε-caprolactone, orδ-valerolactone. Polycarbonate polyols of the above kinds are easilyobtainable as commercial products. For example, are cited Desmophen2020E (made by Sumitomo-Bayer Polyurethane Co., Ltd., average molecularweight 2000), DN-980 (made by Nippon Polyurethane Co., Ltd., averagemolecular weight 2000), and DN-981 (made by Nippon Polyurethane Co.,Ltd., average molecular weight 1000). As the polyether polyols arecited, for example, polyether polyols which are obtained by apolymerization reaction of a cyclic ether such as ethylene oxide,propylene oxide, butylene oxide, and tetrahydrofuran etc. using a diolcompound such as ethylene glycol, propylene glycol, and1,4-butadienediol etc. as an initiator. Polyether polyols of the abovekinds are easily obtainable as commercial products. For example, arecited Sannix PP-1000 (a polypropylene glycol of molecular weight 1000,made by Sanyo Chemical Industries, Ltd.) and PTG-500P (apolytetramethylene glycol of molecular weight 2000, made by HodogayaChemical Kogyo Co., Ltd.). As the polybutadienepolyols are citedpolymers of 1,4-butadiene or 1,2-butadiene having hydroxyl group at aterminal end of the molecule. Also, as the hydrogenated polybutadienepolyethers are cited compounds in which the unsaturated double bonds inthe molecules of said polybutadienepolyols are hydrogenated. Thesecompounds are easily obtainable as commercial products. For example, arecited NISSO-PB G-1000, G-2000, G-3000 (polybutadiene glycol of a liquidtype, made by Nippon Soda Co., Ltd.), NISSO-PB GI-1000, GI-2000, GI-3000(hydrogenated polybutadiene glycol, made by Nippon Soda Co., Ltd.), andPolybd R-45HT (polybutadiene glycol of a liquid type, made by IdemitsuPetro Chemical Co., Ltd.) etc.

As the polymerizable monomers having a carboxyl group, which isseparated from a polymerizable double bond by at least one carbon ormore, in the production method 3, are cited 2-carboxyethyl(meth)acrylate, 4-carboxyphenyl (meth)acrylate, β-(meth)acryloyloxyethylhydrogen phthalate, β-(meth)acryloyloxyethyl hydrogen succinate,β-(meth)acryloyloxypropyl hydrogen phthalate, and (meth)acryloyloxyethyltrimellitic acid etc.

As the polycarboxylic acids in the production method 4 are citedsuccinic acid, adipic acid, phthalic acid, hexahydrophthalic acid,tetrahydrophthalic acid, tricarballylic acid, benzenetricarboxylic acid,and benzenetetracarboxylic acid etc. besides the monoester dicarboxylicacids and polyester polycarboxylic acids exemplified in the productionmethod 2.

As the polymerizable monomers having a hydroxyl group, which is apartfrom a polymerizable double bond by at least one carbon atom or more, inthe production method 4, are cited allyl alcohol, 2-hydroxyethyl(meth)acrylate, 2-hydroxycyclohexyl (meth)acrylate, 2-hydroxybutyl(meth) acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, and 2-hydroxy-3[(2-methyl-1-oxo-2-propenyl)oxy]propylacrylate etc.

As the polymerizable monomers having an epoxy group, which is separatedfrom a polymerizable double bond by at least one carbon atom or more, inthe production method 4, are cited oxiranylmethyl (meth)acrylate,9-oxiranylnonyl (meth)acrylate, (3-methyloxiranyl)methyl (meth)acrylate,and 9,10-epoxyoleyl acrylate (Rikaresin ESA, made by Shin Nippon RikaCo., Ltd.).

As the monoester polyepoxy compounds and polyester polyepoxy compoundsin the production method 5, are cited the reaction products of themonoester dicarboxylic acids and/or polyester polycarboxylic acids withepichlorohydrin exemplified in the production method 2; terephthalicacid diglycidyl ester; o-phthalic acid diglycidyl ester; and thecompounds having the structures below-pictured etc. ##STR14##

As the polymerizable monomers having a functional group capable ofreacting with an epoxy group in the production method 5, are cited(meth)acrylic acid, maleic acid, allyl alcohol, 2-hydroxyethyl(meth)acrylate, vinylethylamine, vinylbutylamine, and aminoethyl (meth)acrylate etc.

Also, the monomer (e) are obtained not only from said productionmethods, but also as commercially-available products. For example, thereare cited KAYARAD MANDA, HX-220, HX-620, R-526, DPCA-20, DPCA-30,DPCA-60, and DPCA-120 (made by Nippon Kayaku Co., Ltd.).

To obtain a water-soluble polymer or a crosslinked polymer in thepresent invention, can be used the monomer (g) capable ofco-polymerizing with the monomers from (i) to (vi), from (ix) to (xiv),and (e) in a range of that the solubility in water of the polymer orcrosslinked polymer and the performance as a cement additive of thecrosslinked polymer are not badly affected, in addition to the abovemonomers from (i) to (vi), from (ix) to (xiv), and (e). The amounts foruse are 0 to 30% by weight against a total amount of the monomers from(i) to (vi), from (ix) to (xiv), and (e).

As examples of the monomer (g) are cited the esters of an aliphaticalcohol of carbon number 1 to 20 with (meth)acrylic acid;(meth)acrylamide; the monoesters or diesters of maleic acid, fumaricacid, or an acid of these kinds with an aliphatic alcohol of carbonnumber 1 to 20, a glycol of carbon number 2 to 4, or a polyalkyleneglycol which is derived with an addition of 2 to 100 moles of saidglycols; alkenyl acetates such as vinyl acetate and propenyl acetateetc.; aromatic vinyl compounds such as styrene and p-methylstyrene etc.;vinyl chloride etc. One kind of these compounds or two kinds or more canbe used in combination.

Besides, in the present invention, a polymer for dispersing cementhitherto known in public may be used as a water-soluble polymer in thepost-crosslinking method. The polymer of such a kind is described in,for example, Japanese Official Patent Gazettes, showa 53-38095,58-38380, and 59-15359, and heisei 2-11542, Japanese Official PatentProvisional Publications, showa 58-74552, 60-16848, 61-209945,63-285141, 63-285142, and heisei 63-236742, and the polymer can be usedas only one kind or in combination of two kinks or more.

In a case of that said monomers from (i) to (vi), from (ix) to (xiv),and (e) are used in combination, although the combination may be setproperly, the setting is carried out, for example, as follows.

(I) the monomers (i) and (xiv).

(II) the monomers (i) and (iv).

(III) the monomers (i), (iv), and (xiv).

(IV) the monomers (i) and (iii).

(V) the monomers (i), (iii), and (xiv).

(VI) the monomers (e), (i), and (xiv).

(VII) the monomers (e), (i), and (iv).

(VII) the monomers (e), (i), (iv), and (xiv).

(IX) the monomers (e), (i), and (iii).

(X) the monomers (e), (i), (iii), and (xiv).

To obtain a crosslinking polymer using these monomers, there are, forexample, a method in which a water-soluble polymer of a straight chaintype is beforehand prepared by polymerizing a monomer which has only onepolymerizing double bond, and the water-soluble polymer and polymer areone another crosslinked by using a crosslinking agent so that saidpolymer makes a main chain (hereinafter, a production method of thiskind may be referred to as "a post-crosslinking method "); and a methodin which a monomer having two or more of a polymerizable double bond anda monomer having only one polymerizable double bond are used incombination and polymerization is carried out simultaneously withcrosslinking (hereinafter, a production method of this kind may bereferred to as "an one-step crosslinking method").

In a case of the post-crosslinking method, for example, any combinationfrom said (I) to (V) may be adopted. In a case of the one-stepcrosslinking method, for example, any combination from said (VI) to (X)may be adopted.

In a case of said combination (I), the monomers (xiv) and (i) arepreferably used in a ratio of 1 to 99.9% by weight of the monomer (xiv)and 99 to 0.1% by weight of the monomer (i) [here, the total of (xiv)and (i) is 100% by weight), and they are more preferably used in such aratio as 50 to 80% by weight of (xiv) and 20 to 50% by weight of (i)[the total of (xiv) and (i) is 100% by weight]. If the amount of (xiv)is too small, an ability to prevent the slump loss may be inferior and,if too much, the air-entraining may become too much. Also, if the amountof (i) is too small, a dispersing ability may be inferior and, if toomuch, retardation of hardening may appear.

In a case of said combination (II), the monomers (iv) and (i) arepreferably used in a ratio of 1 to 99% by weight of the monomer (iv) and1 to 99% by weight of the monomer (i) [here, the total of (iv) and (i)is 100% by weight], and they are more are preferably used in such aratio as 1 to 40% by weight of (iv) and 60 to 99% by weight of (i) [thetotal of (iv) and (i) is 100% by weight]. If the amounts of (iv) or (i)deviate from said % range, the dispersing character may be lacking,material segregation may take place, or the slump loss may increase.

In a case of said combination (III), the monomers (iv), (i), and (xiv)are preferably used in a ratio of 1 to 98% by weight of the monomer(iv), 1 to 98% by weight of the monomer (i), and 1 to 70% by weight ofthe monomer (xiv) [here, the total of (iv), (i), and (xiv) is 100% byweight], and they are more are preferably used in such a ratio as 1 to50% by weight of (iv), 39 to 94% by weight of (i), and 5 to 60% byweight of (xiv) [here, the total of (iv), (i), and (xiv) is 100% byweight]. If any one of (iv), (i), and (xiv) deviates from said % range,lack of the dispersing character, material segregation, increase of theslump loss, or increase of the air amount may take place.

In a case of said combination (IV), the monomers (iii) and (i) arepreferably used in a ratio of 1 to 99% by weight of the monomer (iii)and 1 to 99% by weight of the monomer (i) [here, the total of (iii) and(i) is 100% by weight], and they are more preferably used in such aratio as 1 to 40% by weight of (iii) and 60 to 99% by weight of (i)[here, the total of (iii) and (i) is 100% by weight]. If the amounts of(iii) and (i) deviates from said % range, the dispersing character maybe lacking, material segregation may take place, or the slump loss mayincrease.

In a case of said combination (V), the monomers (iii), (i), and (xiv)are preferably used in a ratio of 1 to 98% by weight of the monomer(iii), 1 to 98% by weight of the monomer (i), and 1 to 70% by weight ofthe monomer (xiv) [here, the total of (iii), (i), and (xiv) is 100% byweight], and they are more preferably used in such a ratio as 1 to 50%by weight of (iii), 39 to 94% by weight of (i), and 5 to 60% by weightof (xiv) [here, the total of (iii), (i), and (xiv) is 100% by weight].If any one of (iii), (i), and (xiv) deviates from said % range, lack ofthe dispersing character, material segregation, increase of the slumploss, or increase of the air amount may take place.

In a case of said combination (VI), the monomers (e), (xiv), and (i) arepreferably used in a ratio of 0.1 to 50% by weight of the monomer (e),from 1 to 98.9% by weight of the monomer (xiv), and 1 to 98.9% by weightof the monomer (i) [here, the total of (e), (xiv), and (i) is 100% byweight].

In a case of said combination (VII), the monomers (e), (iv), and (i) arepreferably used in a ratio of 0.1 to 50% by weight of the monomer (e), 1to 98.9% by weight of the monomer (iv), and 1 to 98.9% by weight of themonomer (i). [the total of (e), (iv), and (i) is 100% by weight.]

In a case of said combination (VII), the monomers (e), (xiv), (iv), and(i) are preferably used in a ratio of 0.1 to 50% by weight of themonomer (e), 1 to 70% weight of the monomer (xiv), 1 to 97.9% by weightof the monomer (iv), and 1 to 97.9% by weight of the monomer (i). [thetotal of (e), (xiv), (iv), and (i) is 100% by weight.] and they are morepreferably used in such a ratio as 1 to 20% by weight of (e), 5 to 59%by weight of (xiv), 1 to 49% by weight of (iv), and 39 to 93% by weightof (i). [the total of (e), (xiv), (iv), and (i) is 100% by weight.]

In a case of said combination (IX), the monomers (e), (iii), and (i)preferably used in a ratio of 0.1 to 50% by weight of the monomer (e), 1to 98.9% by weight of the monomer (iii), and 1 to 98.9% by weight of themonomer (i). [the total of (e), (iii), and (i) is 100% by weight.]

In a case of said combination (X), the monomers (e), (xiv), (iii), and(i) are preferably used in a ratio of 0.1 to 50% by weight of themonomer (e), 1 to 70% weight of the monomer (xiv), 1 to 97.9% by weightof the monomer (iv), and 1 to 97.9% by weight of the monomer (i). [thetotal of (e), (xiv), (iii), and (i) is 100% by weight.] and they aremore preferably used in such a ratio as 1 to 20% by weight of (e), 5 to59% by weight of (xiv), 1 to 49% by weight of (iii), and 39 to 93% byweight of (i). [the total of (e), (xiv), (iii), and (i) is 100% byweight.]

Besides, an use of the monomer (xiv) is favored for preparation of awater-soluble polymer which is superior in an ability to prevent theslump loss. Also, an use of the monomer (iii) is favored for preparationof a water-soluble polymer which is very small in an air-entrainingamount.

In a case of the post-crosslinking method, said monomer component may bepolymerized by using a polymerization initiator in order to prepare saidwater-soluble polymer. The polymerization may be carried out accordingto a polymerization in a solvent or a bulk polymerization.

The polymerization in a solvent may be carried out by a batch system ora continuous system and as a solvent used in the polymerization arecited water; lower alcohols such as methyl alcohol, ethyl alcohol, andisopropyl alcohol etc.; aromatic or aliphatic hydrocarbons such asbenzene, toluene, xylene, cyclohexane, and n-hexane; ethyl acetate;ketone compounds such as acetone and methyl ethyl ketone etc. Fromconsideration of the solubilities of the monomers as the raw materialsand the water-soluble polymers obtained as well as the convenience inuse of the water-soluble prepolymers, it is preferred to use at leastone kind of compound selected from water and lower alcohols of carbonnumber of 1 to 4. Among the lower alcohols of carbon number of 1 to 4,methyl alcohol, ethyl alcohol, and isopropyl alcohol are especiallyeffective.

When the polymerization is carried out in a water medium, awater-soluble polymerization-initiator such as persulfate of ammonium oran alkali metal or hydrogen peroxide etc. is used. At this time, anaccelerator such as sodium hydrogen sulfite etc. may be used incombination with the polymerization-initiator. Also, when thepolymerization is carried out in a solvent such as lower alcohols, anaromatic hydrocarbon, an aliphatic hydrocarbon, ethyl acetate, or aketone compound, a peroxide such as benzoyl peroxide and lauroylperoxide etc., a hydroperoxide such as cumene hydroperoxide etc., and analiphatic azo compound such as azo-bis-isobutyronitrile etc. is used asa polymerization-initiator. At this time an accelerator such as an aminecompound may be used in combination with the polymerization-initiator.Furthermore, when a mixed solvent of water and lower alcohols is used,said various polymerization-initiator or a compound selected from acombination of the polymerization-initiator and an accelerator is usedwith proper selection. Although the polymerization temperature is setdepending upon a solvent and polymerization-initiator used, it isusually in a range of 0° to 120° C.

In the bulk polymerization, a peroxide such as benzoyl peroxide andlauroyl peroxide etc.; a hydroperoxide such as cumene hydroperoxideetc.; and an aliphatic azo compound such as azo-bis-isobutyronitrileetc. is used as a polymerization-initiator and the polymerization iscarried out in a temperature range of 50° to 150° C.

A crosslinking agent used in the present invention is a compound whichhas as a structural unit and/or is capable of forming at least one groupselected from the divalent groups being denoted by said formula (I). Thecrosslinking agent is preferred to be a compound having a functionalgroup which is capable of reacting with a functional group (for example,a carboxyl, hydroxyl, amino, and sulfonate group etc.) of awater-soluble polymer, and there is no special limitation. There arecited, for example, polyalcohols such as ethylene glycol, triethyleneglycol, tetraethylene glycol, polyethylene glycol, glycerol,polyglycerol, propylene glycol, diethanolamine, triethanolamine,polyoxypropylene, oxyethyleneoxypropylene block copolymer,pentaerythritol, sorbitol, sorbitane fatty acid esters etc.; polyvalentglycidyl compounds such as ethylene glycol diglycidyl ether,polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether,diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitolpolyglycidyl ether, pentaerythritolpolyglycidyl ether, propylene glycoldiglycidyl ether, polypropylene glycol diglycidyl ether, resorcinoldiglycidyl ether, 1,6-hexanediol diglycidyl ether, adipic aciddiglycidyl ester, and o-phthalic acid diglycidyl ester etc.

When a polyalcohol is used as a crosslinking agent, a crosslinkedpolymer which has a expected structure can be obtained whenpolymerization of a water-soluble polymer, a monomer which has acarboxyl group at a position which is separated by at least one carbonatom from a polymerizable double bond, for example,2-methacryloyloxyethyl succinate, 2-methacryloyloxyethyl phthalate etc.,is co-polymerized, and then, esterification with polyalcohol being acrosslinking agent is carried out.

In a case of said combination (I), the obtained water-soluble polymerhas a carboxyl group and/or a hydroxyl group. In a case of saidcombination (II), the obtained water-soluble polymer has a carboxylgroup and/or a sulfonate group. In a case of said combination (III), theobtained water-soluble polymer has a carboxyl group and/or a sulfonategroup and/or a hydroxyl group. In a case of said combination (IV), theobtained water-soluble polymer has a carboxyl group and/or a sulfonategroup. In a case of said combination (V), the obtained water-solublepolymer has a carboxyl group and/or a sulfonate group and/or a hydroxylgroup.

The amount for use of a crosslinking agent is preferably from 0.001 to1.0 in a functional group molar ratio against a functional group (acarboxyl group and/or a hydroxyl group and/or a sulfonate group etc.)which said water-soluble polymer has (a functional group of thecrosslinking agent/that of the water-soluble polymer), and morepreferable 0.01 to 0.3. In a case of that the molar ratio is less thansaid range, effect of preventing the slump loss may not be sufficient,the performance of a cement additive in the present invention may not beobtained, and if the molar ratio is more than said range, elevation ofthe performance may not be recognized or handling of the crosslinkedpolymer may be troubled.

To obtain a crosslinked polymer by the post-crosslinking method, forexample, there is a method which comprises a reaction of a water-solublepolymer with a crosslinking agent and the reversed phase suspensionmethod in which a water-soluble polymer is suspended and dispersed in ahydrophobic organic solvent and subjected to a reaction with acrosslinking agent.

Temperature for the reaction of the water-soluble polymer with thecrosslinking agent has no limitation as far as the reaction proceeds,but, for example, a range of 20° to 200° C., especially 50° to 100° C.,is preferred.

Although there is no special limitation for the viscosity of a 20%aqueous solution or water dispersion of the crosslinked polymer whichwas obtained from a reaction of the water-soluble polymer with thecrosslinking agent, the viscosity is preferred if it is 100,000 cps orless when measured by B-type rotational viscometer at 20° C. from astandpoint of production and handling.

To obtain a crosslinked polymer with the one-step crosslinking method,there is suggested a method in which monomers is used in saidcombination from (VI) to (X) and a reaction is carried out under themanners or the conditions which have been mentioned in the production ofthe water-soluble polymers.

The crosslinked polymer may be used by itself as a principal component acement additive and, in case of necessity, it may be neutralized by analkaline substance and then, used as a main component of the cementadditive. As an alkaline substance of this kind are cited, aspreferable, a hydroxide, chloride, and carbonate of a monovalent ordivalent metal; ammonia; and an organic amine.

Also, it is possible for the crosslinked polymer to use in combinationwith other publicly known cement additives. As a known cement additiveof this kind are cited, for example, a hitherto known cement dispersingagent, air-entraining agents, cement wetting and dispersing agents,water-resisting agents, strength-enhancing agents, and accelerators.

The cement additive in the present invention may be used for hydrauliccement such as portland cement, alumina cement, and various kinds ofmixed cement, or a hydraulic material besides the cement such as gypsumetc.

As a method for use of the cement additive of the present invention arereferred, for example, to a method in which the additive is dissolved inwater for mixing and kneading and then, is added during preparation of acement composition together with the water for mixing and kneading, andto a method in which the additive is added to a cement composition thathas been already kneaded up.

The amount of the cement additive is recommended to be from 0.005 to2.5% against the cement in the cement composition as a weight % of asolid portion. If the amount is less than 0.005%, a property to preventa slump loss may not be obtained. Also, if it becomes such a largeamount exceeding 2.5%, there may occur such a problem as an economicaldisadvantage or a coagulation delay and an excess of entrained air.

A mechanism of slump loss prevention by the present invention may beassumed as follows. In general, a cement additive having a speciallydefined functional group is strongly adsorbed on cement particles andthus, these particles are dispersed effectively into water. However, asa hydration reaction of cement further proceeds, a precipitating mineralwhich newly forms on the cement particles (ettringite etc.) adsorbs andaccomodates the dispersing agent, the concentration of the cementadditive in the solution decreases, and flocculation of the cementparticles progresses. For prevention of this, the additive needs to besupplied by any means so that the cement additive concentration does notdecrease in the system.

Thus, the present inventors carried out extensive research and, as aresult, an additive was developed which, immediately after mixing andkneading in cement paste, shows only a weak adsorption ability forcement due to the molecular size of the crosslinked polymer and, withpassage of time, is going to be cut by an outside action (for example,hydrolysis with an alkali) into molecules having an adsorption ability.Considering that the cement additive in the present invention is addedinto cement paste, an aqueous solution of a crosslinked polymer, that isa cement additive, is adjusted at pH 12 and stood with stirring at roomtemperature. As a result, the gel permeation chromatography (GPC) whichshows molecular weight distribution of the crosslinked polymer variesgreatly as shown in comparison between FIG. 1 and FIG. 2 and among FIGS.3, 4, and 5.

Since the crosslinked polymer has the above specified bond between themain chains, the crosslinking bond is gradually cut in an alkalinemedium. This is the reason why an ester bond in the above specified bondgradually undergoes hydrolysis by alkali. According to this, dispersionof cement is maintained for a long time.

Besides, a crosslinking agent or monomer (e) is able to have saidspecified bond, and this is able to be formed by a reaction between thecrosslinking agent and the water-soluble polymer in thepost-crosslinking method. For example, in a case that between acrosslinking agent and a water-soluble polymer the one has a carboxylgroup and the other has an epoxy group, the bond having a structureshown by said formula (I) is produced by a reaction of the crosslinkingagent and water-soluble polymer.

On the other hand, since an ester bond which is directly bound to themain chain position and does not have a structure as shown by saidformula (I) does not undergo cleavage in the above temperature rangeeven in an alkali medium, to maintain the cement dispersion for a longtime is difficult and the ability to prevent the slump loss is inferior.

However, even though an ester bond is directly bound to the main chainposition, if a hydroxy group is bound to a carbon atom position which isseparated by one carbon atom from the ester bond, a hydrophiliccharacter and an effect favorable for a hydrolysis reaction is obtaineddue to the hydroxyl group and, as a result, the ability to prevent theslump loss is elevated. A structure of this kind is formed, for example,with a reaction of a carboxyl group with an epoxy group. Thecrosslinking agent and monomer (e) leading a structure of this kind areexemplified as follows.

As the crosslinking agent, are cited ethylene glycol diglycidyl ether,polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether,diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitolpolyglycidyl ether, pentaerythritol polyglycidyl ether, propylene glycoldiglycidyl ether, polypropylene glycol diglycidyl ether, resorcinoldiglycidyl ether etc.

As the monomer (e), are cited monomers having the following structure.##STR15##

Besides, for the cement additive in the present invention thecrosslinked polymer may be dissolved or dispersed. Here, the worddispersion means that, for example, a microgel and so on which areby-produced during the production of the crosslinked polymer aredispersed in water. If the crosslinked polymer is, as above, dissolvedor dispersed in water, it has an advantage of easy handling, the cementadditive is used during preparation of the cement composition as a partor whole of the water for mixing and kneading. In addition, there doesnot take place such a problem as trouble in the dispersing stability(sedimentation etc.) which has often been observed in the hetherto-knowncement additive.

In the case that said specific crosslinked polymer is dissolved ordispersed in water beforehand, the ratio of the crosslinked polymer tothe water-soluble polymer may be optionally set and there is no speciallimitation.

The cement additive of the present invention is able to optionallycontrol an extent of the ability to prevent the slump loss in a chemicalsense by that the crosslinking agent or the monomer (e) is changed orthe kind of crosslinking agents or the monomer (e) is changed andcombined. This fact is a very superior point in view of that other kindsof additives which have aimed the preventing effect on the s lump lossshow difficulty or impossibility in controlling the ability to preventthe slump loss. For example, in a method of that a copolymer of olefinwith an ethylenic unsaturated dicarboxylic acid anhydride graduallyundergoes a hydrolysis reaction in a cement composition (JapaneseOfficial Patent Provisional Publication, showa 60-16851), it isnecessary to enlarge the particle diameter of the copolymer in order tomaintain the ability to prevent the slump loss for a long period andthereby, there takes place sedimentation of particles in the additive.The crosslinked polymer in which a small amount of a crosslinking agentor the monomer (e) is contained is a liquid of relatively low viscosityand, therefore, it has a fundamentally good stability, while other kindsof additives which intend a preventive effect on the slump loss need touse a substance in a different phase with mixing and dispersing, so thatthese are of bad stability.

However, the cement additive of the present invention does not sufferany limitation by the above reason.

The cement additive of the present invention, as used in various cementcompositions such as cement mortar and concrete etc., enables thecomposition to manifest high flowability without largely retarding theirsetting and prevent themselves from undergoing slump loss. Thus, itbrings significant improvement in the workability when mortar work orconcrete work being carried out.

Therefore, the cement additive in the present invention, of course, canbe used effectively as an agent for imparting flowability to concrete,for example, ready-mixed concrete, and also its most characteristicpoint is that as an air-entraining high range water-reducing additive ofsimultaneous addition to plant, production of ready-mixed concretehaving a composition of high ratio of water-reduction can be facilitatedand flowability of the concrete can be maintained as constant.Furthermore, it can be used effectively as a high range water-reducingadditive for producing a secondary concrete product.

Furthermore, as other examples, the additive is able to be effectivelyused, for example, for an assistant for grout of cement milk or mortar,and maintaining of flowing and prevention of material segregation etc.of a cement composition placed by a tremie pipe, an under waterconcrete, a concrete for a continuous under ground wall etc.

The method for producing a cement additive of the present invention iseasy in making a design for a structure of a crosslinked polymer or awater-soluble polymer in a case of that the post-crosslinking method isused, and is able to produce a crosslinked polymer in a relatively fewerprocesses when the one-step crosslinking method is used, compared tothose in the post-crosslinking method.

Since the cement composition relating to the present invention containssaid specially defined cement additive, it does not bring a slump losswithout causing a strength decrease in a hardening product and,therefore, it is so stable irrespective of passage of time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a GPC eluding curve for a crosslinked polymer which wasobtained from the example 1.

FIG. 2 is a GPC eluding curve for an aqueous solution of the samecrosslinked polymer which was adjusted to pH 12 by adding an aqueoussodium hydroxide solution and stirred at room temperature for 10minutes.

FIG. 3 is a GPC eluding curve for a copolymer which was obtained fromthe example 85.

FIG. 4 is a GPC eluding curve for an aqueous solution of the samecopolymer which was adjusted to pH 12 by adding an aqueous sodiumhydroxide solution and stirred at room temperature for 30 minutes.

FIG. 5 is a GPC eluding curve for an aqueous solution of the samecopolymer which was adjusted to pH 12 by adding an aqueous sodiumhydroxide solution and stirred at room temperature for 120 minutes.

BEST MODE FOR CARRYING OUT THE INVENTION

Next, the cement additive, the method for producing the same, and thecement composition of the present invention are explained in more detailwith the following examples, but the present invention is not limitedwithin these examples. Besides, unless otherwise specially stated, the %indicates a weight % and the part indicates a weight part. Hereinafter,a crosslinked polymer is referred to as a hydrophilic resin or acopolymer.

EXAMPLE 1

Into a glass-made reaction vessel equipped with a thermometer, astirrer, dropping funnels, and a gas-inlet tube, and a reflux condenserwere placed 164.2 parts of water, the inside atmosphere of the flask wasreplaced with stirring by nitrogen gas, and the flask was warmed to theboiling point under a nitrogen atmosphere. Then, to this were added amixture solution composed of 62.9 parts of methoxypolyethylene glycolmonomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICAL Co.,Ltd.; an average mole number of added ethylene oxide is 9), 16.7 partsof methacrylic acid, and 125.5 parts of water and, in addition, 24.6parts of a 2.5% aqueous ammonium persulfate solution during 4 hours.After the addition finished, furthermore, 6.1 parts of 2.5% aqueousammonium persulfate solution were added during 1 hour. After theaddition completed, the mixture was maintained at the boiling point for1 hour to complete a polymerization reaction, whereby a water-solublepolymer (1) was obtained. Then, to this polymer were added 3.2 parts ofo-phthalic acid diglycidyl ester ("DENACOL EX-721", made by NAGASECHEMICALS Co., Ltd.) and the mixture was maintained at the boiling pointfor 3 hours to complete a reaction. Then, the reaction mixture wascompletely neutralized with an aqueous sodium hydroxide, whereby ahydrophilic resin (1) was obtained.

EXAMPLE 2

The procedure of example 1 was repeated except that parts of o-phthalicacid diglycidyl ester, which is a polyfunctional compound, was 1.6parts, whereby a hydrophilic resin (2) was obtained.

EXAMPLE 3

The procedure of example 1 was repeated except that 11.4 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-861", made by NAGASECHEMICALS Co., Ltd.; an average mole number of added ethylene oxide isabout 22) were added instead of the o-phthalic acid diglycidyl ester,whereby a hydrophilic resin (3) was obtained.

EXAMPLE 4

The procedure of the example 1 was repeated except that 3.2 parts ofadipic acid diglycidyl ester ("DENACOL EX-701", made by NAGASE CHEMICALSCo., Ltd.) were added instead of the o-phthalic acid diglycidyl ester,whereby a hydrophilic resin (4) was obtained.

EXAMPLE 5

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 17.6 parts of 2-hydroxyethyl methacrylate (hereinafterreferred to as HEMA), 14.4 parts of methacrylic acid, 1.0 part ofbenzoyl peroxide (hereinafter referred to as BPO), and 127 parts ofisopropyl alcohol (hereinafter referred to as IPA) and the insideatmosphere of the flask was replaced with stirring by nitrogen gas andthe flask was warmed up to the boiling point. Next, to this flask wasadded during 2 hours a mixture solution composed of 20.9 parts of HEMA,17.1 parts of methacrylic acid, 1.1 parts of BPO, and 150.9 parts of IPAand, after those addition finished, were further added during 1 hour10.7 parts of a 7% IPA solution of BPO. After this addition finished,the mixture was further maintained at the boiling point for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer (2)was obtained. Next, to this were added 6.0 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the mixture was maintained at the boiling point for 3 hours tocomplete a reaction and then, completely neutralized with an aqueoussodium hydroxide solution and treated with distillation to remove IPA,whereby a hydrophilic resin (5) was obtained.

EXAMPLE 6

The procedure of example 5 was repeated except that 21.5 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-861", made by NAGASECHEMICALS Co., Ltd.; an average mole number of added ethylene oxide isabout 22) was added instead of o-phthalic acid diglycidyl ester, wherebya hydrophilic resin (6) was obtained.

EXAMPLE 7

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 164.2 parts of water and the inside atmosphere of the flaskwas replaced with stirring with nitrogen gas and the flask was warmed upto the boiling point under a nitrogen atmosphere. Next, to this wereadded a mixture solution composed of 62.9 parts of polyethylene glycolpolypropylene glycol methacrylate "Blenmer 70PEP-350B", made by NIPPONOIL & FATS Co., Ltd.; an average mole number of added ethylene oxide is7 and an average mole number of added propylene oxide is 3), 16.7 partsof methacrylic acid, and 125.5 parts of water, with 24.6 parts of a 2.5%aqueous ammonium persulfate solution during 4 hours and, after theaddition finished, 6.1 parts of a 2.5% aqueous ammonium persulfatesolution were further added during 1 hour. After the addition finished,the mixture was further maintained at the boiling point for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer (3)was obtained. Next, to this were added 12.8 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)the mixture was maintained at the boiling point for 3 hours to completea crosslinking reaction, whereby a hydrophilic resin (7) was obtained.

EXAMPLE 8

The procedure of example 7 was repeated except that 0.64 parts ofo-phthalic acid diglycidyl ester of a polyfunctional type compound wasused, whereby a hydrophilic resin (8) was obtained.

EXAMPLE 9

The procedure of example 7 was repeated except that 11.4 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-861", made by NAGASECHEMICALS Co., Ltd.; an average mole number of added ethylene oxide isabout 22) was added instead of the o-phthalic acid diglycidyl ester usedin the example 7, whereby a hydrophilic resin (9) was obtained.

EXAMPLE 10

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 460.7 parts of water and the inside atmosphere of the flaskwas replaced with stirring with nitrogen gas and the flask was warmed upto 50° C. under the nitrogen atmosphere. In this flask was added amixture solution composed of 191.2 parts of methoxypolyethylene glycolmonomethacrylate ("NK-ester M-23G", made SHIN-NAKAMURA by CHEMICAL Co.,Ltd.; an average mole number of added ethylene oxide is 23), 8.0 partsof methacrylic of a acid, 8.7 parts 16.5% aqueous sodium hydroxidesolution, and 304.9 parts of water and furthermore, were added 11.8parts of a 15% aqueous ammonium persulfate solution and 5.9 parts of a15% aqueous sodium hydrogen sulfite solution during 2 hours and, afterthe addition finished, were further added 5.9 parts of a 15% aqueousammonium persulfate solution and 2.9 parts of a 15% aqueous sodiumhydrogen sulfite solution during 1 hour. After the addition finished,the reaction mixture was kept at 50° C. for 1 hour to complete apolymerization reaction, whereby a water-soluble polymer (4) wasobtained. To this were added 13.8 parts of o-phthalic acid diglycidylester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and themixture was maintained at the boiling point for 3 hours to complete areaction, whereby a hydrophilic resin (10) was obtained.

EXAMPLE 11

The procedure of example 10 was repeated except that 27.3 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-861", made by NAGASECHEMICALS Co., Ltd.; an average mole number of added ethylene oxide isabout 22) was added instead of the o-phthalic acid diglycidyl ester usedin the example 10, whereby a hydrophilic resin (11) was obtained.

EXAMPLE 12

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 216.2 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 90° C. under the nitrogen atmosphere. To this was added a mixturesolution composed of 20.0 parts of methoxypolyethylene glycolmonomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICAL Co.,Ltd.; an average mole number of added ethylene oxide is 9), 86.2 partsof methacrylic acid, 72.1 parts of sodium methacrylate, and 278.9 partsof water, and furthermore, were added 137.0 parts of a 15% aqueousammonium persulfate solution and 58.0 parts of a 15% aqueous sodiumhydrogen sulfite solution during 4 hours and, after the additionfinished, were added 34.3 parts of a 15% aqueous ammonium persulfatesolution and 27.3 parts of a 15% aqueous sodium hydrogen sulfitesolution during 1 hour. After the addition finished, the mixture wasfurther maintained at 90° C. for 1 hour to complete a polymerizationreaction, whereby a water-soluble polymer (5) was obtained. Next, tothis were added 14.1 parts of o-phthalic acid diglycidyl ester ("DENACOLEX-721", made by NAGASE CHEMICALS Co., Ltd.) and the reaction mixturewas maintained at the boiling point for 3 hours to complete a reactionand then, completely neutralized with an aqueous sodium hydroxidesolution, whereby a hydrophilic resin (12) was obtained.

EXAMPLE 13

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 568.7 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. To this was added amixture solution composed of 40.0 parts of methoxypolyethylene glycolmonomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICAL Co.,Ltd.; an average mole number of added ethylene oxide is 9), 127.4 partsof methacrylic acid, and 261.8 parts of water, and furthermore, wereadded 156.6 parts of a 2.5% aqueous sodium persulfate solution during 4hours and, after the addition finished, the mixture was furthermaintained at the boiling point for 1 hour to complete a polymerizationreaction, whereby a water-soluble polymer (6) was obtained. Next, tothis were added 7.33 parts of o-phthalic acid diglycidyl ester ("DENACOLEX-721", made by NAGASE CHEMICALS Co., Ltd.) and the reaction mixturewas maintained at the boiling point for 3 hours to complete a reactionand then, completely neutralized with an aqueous sodium hydroxidesolution, whereby a hydrophilic resin (13) was obtained.

EXAMPLE 14

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 176.4 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. To this was added amixture solution composed of 62.9 parts of methoxypolyethylene glycolmonomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICAL Co.,Ltd.; an average mole number of added ethylene oxide is 9), 16.7 partsof methacrylic acid, and 125.5 parts of water, and 14.8 parts of a 2.5%aqueous ammonium persulfate solution during 4 hours and, after theaddition finished, were added 3.7 parts of a 2.5% aqueous ammoniumpersulfate solution during 1 hour. After the addition finished, themixture was further maintained at the boiling point for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer (7)was obtained. Next, to this were added 0.64 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the reaction mixture was maintained at the boiling point for 3 hoursto complete a reaction and then, completely neutralized with an aqueoussodium hydroxide solution, whereby a hydrophilic resin (14) wasobtained.

EXAMPLE 15

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 164.2 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. To this was added amixture solution composed of 62.9 parts of methoxypolyethylene glycolmonomethacrylate (an average mole number of added ethylene oxide is 10),16.7 parts of acrylic acid, and 125.5 parts of water, and 24.6 parts ofa 2.5% aqueous ammonium persulfate solution during 4 hours and, afterthe addition finished, were added 6.1 parts of a 2.5% aqueous ammoniumpersulfate solution during 1 hour. After the addition finished, themixture was further maintained at the boiling point for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer (8)was obtained. Next, to this were added 3.2 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the reaction mixture was maintained at the boiling point for 3 hoursto complete a reaction and then, completely neutralized with an aqueoussodium hydroxide solution, whereby a hydrophilic resin (15) wasobtained.

EXAMPLE 16

The procedure of example 1 was repeated except that 3.2 parts of acompound having the following structure ("DENACOL EX-202", made byNAGASE CHEMICALS Co., Ltd.) were added instead of the o-phthalic aciddiglycidyl ester used in the example 1, whereby a hydrophilic resin (16)was obtained. ##STR16##

EXAMPLE 17

The procedure of example 1 was repeated except that 3.2 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-841", made by NAGASECHEMICALS Co., Ltd.; an average mole number of added ethylene oxide isabout 13) were added instead of the o-phthalic acid diglycidyl esterused in the example 1, whereby a hydrophilic resin (17) was obtained.

EXAMPLE 18

The procedure of example 1 was repeated except that 3.2 parts ofsorbitol polyglycidyl ether ("DENACOL EX-611", made by NAGASE CHEMICALSCo., Ltd.) were added instead of the o-phthalic acid diglycidyl esterused in the example 1, whereby a hydrophilic resin (18) was obtained.

The average molecular weights (weight average) of the water-solublepolymers above-obtained were determined by GPC and shown in Table 1. Theconditions of GPC are as follows;

Column: TOSOH TSK gel G4000SW+G3000SW+G2000SW;

Eluent: [0.05M-CH₃ COONa aqueous solution (adjusted to pH 6.0 by CH₃COOH)]/acetonitrile =59/41 (vol. %);

Temperature: 40° C.;

Flow rate: 0.5 ml/min.;

Standard compound: polyethylene glycol.

Also, viscosity of the hydrophilic resins above-obtained was measuredwith a B-type rotational visocometer (VG-A1 type, made by SEIKI KOGYORESEARCH Co., Ltd.), and results obtained are shown in the Table 1. Theviscosity measurement was carried out about prepared 20% aqueoussolutions or dispersions of the hydrophilic resins at a temperature of20° C. with a rotation number of 60 r.p.m. in case that the viscosity ofthe resin solutions or dispersions was 10,000 cps or less, or with arotation number of 6 r.p.m. in case that the viscosity was 10,000 to100,000 cps.

EXAMPLE 19

Ordinary portland cement (made by Sumitomo Cement Co., Ltd.) was used ascement, river sand taken from Yodogawa as a a fine aggregate (specificgravity of 2.51 and a fineness modulas [F. M.] of 2.78), crashed stonesfrom Takatsuki as a coarse aggregate (specific gravity of 2.68 and afineness modulas [F. M.] of 6.73), and the hydrophilic resin (1)obtained in the example 1 as a cement additive, and these materials wererespectively weighted to make 30 1 in amount of a kneaded mixture with acomposition of a unit ratio of 320 kg/m³ for cement, a unit ratio of 173kg/m³ for water (a ratio of water to cement, 54.2%), a unit ratio of 934kg/m³ for fine aggregate, a unit ratio of 876 kg/m³ for coarse aggregate(a fine aggregate percentage of 52%), and an addition amount 0.12% ofthe hydrophilic resin (1) obtained from the example 1 (a ratio of thesolid portion against cement), and then all the materials were placedinto a tilting mixer. Immediately, the mixing and kneading were carriedout for 3 minutes with 35 r.p.m. of a rotation number, whereby a fluidconcrete having an object slump 18 cm and an object air amount 4.5% wasprepared (in a case of that the object air amount is not attained, aslight amount of an air-entraining agent [Vinsol], made by YamasoChemical Co., Ltd. was used). A fluid concrete immediately after themixing and kneading was sampled and the slump and air amount weremeasured.

After the mixing and kneading, the rotation number of the tiltingmixture was reduced to 3 r. p.m. and the mixing and kneading was furthercontinued and then, after 60 minutes, 90 minutes, and 120 minutes, theslump and air amount were measured to investigate their changes withtime-passage.

Also, the condensation strength and setting time of the flowing concreteobtained were measured. These measurement results are presented in Table1.

Besides, the measurement methods for the slump, air amount, compressivestrength, and setting time, and the method to take a sample for testingthe compressive strength are based on the Japanese Industrial Standards(JIS A6204).

EXAMPLES 20 TO 36

The procedure of example 19 were repeated except that the hydrophilicresins (2) to (18) obtained from the examples 2 to 18 are used as cementadditives in the amounts shown in Table 1, and flowing concretesthus-prepared were measured in the slump, air amount, compressivestrength, and setting time. Results obtained are shown in Table 1.

Example for comparison 1

The procedure of example 19 was repeated except that acommercially-available sodium naphthalenesulfonate-formalin condensationproduct was used in an addition amount of 0.35% (against cement) as acement additive instead of the hydrophilic resin (1), and a flowingconcrete for comparison thus-prepared was measured in the slump, airamount, compressive strength, and setting time. Results obtained areshown in Table 1.

Example for comparison 2

The procedure of example 19 was repeated except thatcommercially-available sodium ligninsulfonate was used in an additionamount of 0.35% (against cement) as a cement additive instead of thehydrophilic resin (1), and a flowing concrete for comparisonthus-prepared was measured in the slump, air amount, compressivestrength, and setting time. Results obtained are shown in Table 1.

Example for comparison 3

The procedure of example 19 was repeated except that the water-solublepolymer (1) obtained from the example 1 was used in an addition amountof 0.12% (against cement) as a cement additive instead of thehydrophilic resin (1), and a flowing concrete for comparisonthus-prepared was measured in the slump, air amount, compressivestrength, and setting time. Results obtained are shown in Table 1.

Example for comparison 4

The procedure of example 19 was repeated except that acommercially-available sodium naphthalenesulfonate-formalin condensationproduct and a water-highly absorbent resin (a crosslinked product ofpartially neutralized polyacrylic acid) was used in addition amounts of0.35% and 0.1% (against cement), respectively, as cement additivesinstead of the hydrophilic resin (1), and a flowing concrete forcomparison thus-prepared was measured in the slump, air amount,compressive strength, and setting time. Results obtained are shown inTable 1.

                                      TABLE 1                                     __________________________________________________________________________                                           The upper side: Slump (cm)                     Water-soluble                                                                          Cement admixture used The middle side: Air amount (%)                polymer              Addition amount                                                                         The under side: Residual % of                                                 slump(*3)                                         Molecular    Viscosity                                                                          (solid portion, %)                                                                      Immediately                                                                           after 60                                                                           after                                                                              after 120                    No.                                                                              weight(*1)   (cps)(*2)                                                                          (against cement)                                                                        after kneading                                                                        minutes                                                                            minutes                                                                            minutes              __________________________________________________________________________    Example 19                                                                            (1)                                                                              20,000                                                                              Hydrophilic                                                                          3,500                                                                              0.12      17.7    19.3 18.5 17.8                                  resin                 4.9     5.2  5.1  4.8                                    (1)                  --      109  105  101                  Example 20                                                                            (1)                                                                              20,000                                                                              Hydrophilic                                                                            30 0.12      18.7    18.5 18.3 17.6                                  resin                 4.3     4.6  4.3  4.0                                    (2)                  --      99   98   94                   Example 21                                                                            (1)                                                                              20,000                                                                              Hydrophilic                                                                          1,010                                                                              0.12      18.0    17.0 15.8 12.3                                  resin                 4.8     4.9  5.0  4.8                                    (3)                  --      94   88   68                   Example 22                                                                            (1)                                                                              20,000                                                                              Hydrophilic                                                                          3,000                                                                              0.12      18.4    18.9 18.0 17.2                                  resin                 4.6     4.9  5.0  4.7                                    (4)                  --      103  98   93                   Example 23                                                                            (2)                                                                              23,000                                                                              Hydrophilic                                                                          2,800                                                                              0.18      18.3    17.7 17.5 17.1                                  resin                 4.1     4.3  4.3  4.0                                    (5)                  --      97   96   93                   Example 24                                                                            (2)                                                                              23,000                                                                              Hydrophilic                                                                            120                                                                              0.18      17.8    16.6 15.0 11.8                                  resin                 4.6     4.9  4.9  4.6                                    (6)                  --      93   84   66                   Example 25                                                                            (3)                                                                              18,000                                                                              Hydrophilic                                                                            82 0.14      17.3    20.2 19.8 18.8                                  resin                 4.8     4.9  5.0  4.7                                    (7)                  --      117  114  109                  Example 26                                                                            (3)                                                                              18,000                                                                              Hydrophilic                                                                            30 0.10      18.8    17.0 16.8 16.6                                  resin                 4.8     5.2  5.2  5.0                                    (8)                  --      90   89   88                   Example 27                                                                            (3)                                                                              18,000                                                                              Hydrophilic                                                                            39 0.12      18.5    17.3 15.4 11.2                                  resin                 4.9     5.3  5.1  4.8                                    (9)                  --      94   83   61                   Example 28                                                                            (4)                                                                              26,000                                                                              Hydrophilic                                                                            76 0.20      17.5    18.3 18.0 17.3                                  resin                 4.0     4.3  4.5  4.2                                   (10)                  --      105  103  99                   Example 29                                                                            (4)                                                                              26,000                                                                              Hydrophilic                                                                            46 0.20      18.3    17.1 14.9 10.8                                  resin                 4.5     4.9  4.7  4.4                                   (11)                  --      93   81   59                   Example 30                                                                            (5)                                                                              15,000                                                                              Hydrophilic                                                                            33 0.30      17.4    18.0 17.8 17.2                                  resin                 3.8     3.5  3.6  3.4                                   (12)                  --      103  102  99                   Example 31                                                                            (6)                                                                              18,000                                                                              Hydrophilic                                                                            180                                                                              0.15      19.0    17.0 17.2 17.0                                  resin                 5.3     4.8  4.9  4.3                                   (13)                  --      89   91   89                   Example 32                                                                            (7)                                                                              87,000                                                                              Hydrophilic                                                                          2,600                                                                              0.16      18.2    18.4 18.0 17.2                                  resin                 4.1     4.7  4.8  4.6                                   (14)                  --      101  99   95                   Example 33                                                                            (8)                                                                              18,000                                                                              Hydrophilic                                                                          3,500                                                                              0.12      18.3    17.9 17.5 17.1                                  resin                 4.8     5.2  4.9  4.6                                   (15)                  --      98   96   93                   Example 34                                                                            (1)                                                                              20,000                                                                              Hydrophilic                                                                          6,000                                                                              0.25      5.0     18.0 19.5 18.3                                  resin                 3.2     5.9  5.9  5.8                                   (16)                  --      360  390  366                  Example 35                                                                            (1)                                                                              20,000                                                                              Hydrophilic                                                                          4,000                                                                              0.40      18.0    17.5 16.1 12.7                                  resin                 4.1     4.3  4.5  4.0                                   (17)                  --      97   89   71                   Example 36                                                                            (1)                                                                              20,000                                                                              Hydrophilic                                                                          4,800                                                                              0.12      18.2    16.8 14.2 10.4                                  resin                 4.8     4.9  4.6  4.2                                   (18)                  --      92   78   57                   Example for                                                                           -- --    NSF(*4)                                                                              --   0.35      18.6    8.3  --   --                   comparison 1                           4.3     4.0  --   --                                                          --      45   --   --                   Example for                                                                           -- --    LS(*5) --   0.35      18.8    9.8  --   --                   comparison 2                           5.2     5.6  --   --                                                          --      52   --   --                   Example for                                                                           -- --    Water-soluble                                                                        --   0.12      18.3    13.3 --   --                   comparison 3     polymer (1)           4.4     4.8  --   --                                                          --      73   --   --                    Example for                                                                           --                                                                               --    NSF +  --   0.35      17.4    10.4                                                                               --   --                  comparison 4     High water  0.10      5.3     6.0  --   --                                    absorbent             --      60   --   --                                    resin(*6)                                                    __________________________________________________________________________                                                    Condensation                                                                          Setting time                                                          strength                                                                              (hour:minute)                                                         age of 28                                                                             (beginning/                                                           days (kg/cm.sup.2)                                                                    finishing)            __________________________________________________________________________                                            Example 19                                                                            352     5:25/7:18                                                     Example 20                                                                            340     5:17/7:08                                                     Example 21                                                                            360     5:10/7:11                                                     Example 22                                                                            325     5:23/7:10                                                     Example 23                                                                            320     5:05/7:03                                                     Example 24                                                                            328     5:17/7:20                                                     Example 25                                                                            365     5:36/7:29                                                     Example 26                                                                            332     5:18/7:21                                                     Example 27                                                                            315     5:27/7:13                                                     Example 28                                                                            310     5:10/7:07                                                     Example 29                                                                            327     5:40/7:28                                                     Example 30                                                                            310     6:10/8:05                                                     Example 31                                                                            323     5:13/7:13                                                     Example 32                                                                            330     5:08/7:18                                                     Example 33                                                                            340     5:15/7:23                                                     Example 34                                                                            343     5:52/7:49                                                     Example 35                                                                            329     5:30/7:28                                                     Example 36                                                                            338     5:24/7:19                                                     Example for                                                                           321     5:13/7:01                                                     comparison 1                                                                  Example for                                                                           334     5:24/7:18                                                     comparison 2                                                                  Example for                                                                           320     5:21/7:31                                                     comparison 3                                                                  Example for                                                                           313     7:10/9:45                                                     comparison 4                          __________________________________________________________________________     (*1)Measured by G.P.C.                                                        (*2)Measured by a B type rotational viscometer at 20° C. and 20%       ##STR17##                                                                     (*4)NSF: Sodium naphthalenesulfonateformalin condensation product             (*5)LS: Sodium ligninsulfonate                                                (*6)a partially neutralized crosslinked product of polyacrylic acid      

EXAMPLE 37

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 147.4 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 90° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 48.0 parts of methacrylic acid and 75.1 parts ofwater, a mixture solution composed of 32.0 parts of2-acrylamido-2-methylpropanesulfonic acid and 50.1 parts of water, and31.6 parts of a 15% aqueous ammonium persulfate solution during 2 hoursand, after the addition finished, were added 15.8 parts of a 15% aqueousammonium persulfate solution during 1 hour. After the addition finished,the mixture was further maintained at 90° C. for 1 hour to complete apolymerization reaction, whereby a water-soluble polymer (37) wasobtained. Next, to this were added 46.2 parts of water and 5.63 parts ofo-phthalic acid diglycidyl ester ("DENACOL EX-721", made by NAGASECHEMICALS Co., Ltd.) and the reaction mixture was maintained at theboiling point for 3 hours to complete a reaction and then, completelyneutralized with an aqueous sodium hydroxide solution, whereby ahydrophilic resin (37) was obtained.

EXAMPLE 38

The procedure of example 37 was repeated except that 20.8 parts ofo-phthalic acid diglycidyl ester for the crosslinking agent were used,whereby a hydrophilic resin (38) was obtained.

EXAMPLE 39

The procedure of example 37 was repeated except that 6.00 parts ofadipic acid diglycidyl ester ("DENACOL EX-701", made by NAGASE CHEMICALSCo., Ltd.) were added instead of the o-phthalic acid diglycidyl esterused in the example 37, whereby a hydrophilic resin (39) was obtained.

EXAMPLE 40

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 147.4 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 90° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 48.0 parts of methacrylic acid and 75.1 parts ofwater, a mixture solution composed of 32.0 parts of2-acrylamido-2-methylpropanesulfonic acid and 50.1 parts of water, and31.7 parts of a 30.0% aqueous ammonium persulfate solution during 2hours and, after the addition finished, 15.8 parts of a 30.0% aqueousammonium persulfate solution during 1 hour. After the addition finished,the mixture was further maintained at 90° C. for 1 hour to complete apolymerization reaction, whereby a water-soluble polymer (38) wasobtained. Next, to this were added 2.24 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the reaction mixture was maintained at the boiling point for 3 hoursto complete a reaction and then, completely neutralized with an aqueoussodium hydroxide solution, whereby a hydrophilic resin (40) wasobtained.

EXAMPLE 41

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 147.4 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 90° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 48.0 parts of methacrylic acid and 75.1 parts ofwater, a mixture solution composed of 32.0 parts of2-acrylamido-2-methylpropanesulfonic acid and 50.1 parts of water, and31.6 parts of a 7.5% aqueous ammonium persulfate solution during 2 hoursand, after the addition finished, 15.8 parts of a 7.5% aqueous ammoniumpersulfate solution during 1 hour. After the addition finished, themixture was further maintained at 90° C. for 1 hour to complete apolymerization reaction, whereby a water-soluble polymer (39) wasobtained. Next, to this were added 1.88 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the reaction mixture was maintained at the boiling point for 3 hoursto complete a reaction and then, completely neutralized with an aqueoussodium hydroxide solution, whereby a hydrophilic resin (41) wasobtained.

EXAMPLE 42

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 614.4 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 90° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 324.0 parts of methacrylic acid and 506.8 parts ofwater, a mixture solution composed of 36.0 parts of2-acrylamido-2-methylpropanesulfonic acid and 56.3 parts of water, and175.0 parts of a 15% aqueous ammonium persulfate solution during 2 hoursand, after the addition finished, were further added 87.5 parts of a 15%aqueous ammonium persulfate solution during 1 hour. After the additionfinished, the mixture was further maintained at 90° C. for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer (40)was obtained. Next, to this were added 62.5 parts of o-phthalic aciddiglycidyl ester (" DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the reaction mixture was maintained at the boiling point for 3 hoursto complete a reaction and then, completely neutralized with an aqueoussodium hydroxide solution, whereby a hydrophilic resin (42) wasobtained.

EXAMPLE 43

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed a mixture composed of 14.4 parts of 2-hydroxyethylmethacrylate, 3.2 parts of 2-acrylamido-2-methylpropanesulfonic acid,14.4 parts of methacrylic acid, 0.96 parts of BPO, and 127.0 parts ofIPA and the inside atmosphere of the flask was replaced with stirring bynitrogen gas and the mixture was warmed up to the boiling point. Next,to this flask was added during 2 hours a mixture composed of 17.1 partsof 2-hydroxyethyl methacrylate, 3.8 parts of2-acrylamido-2-methylpropanesulfonic acid, 17.1 parts of methacrylicacid, 1.14 parts of BPO, and 150.9 parts of IPA and, after thoseaddition finished, were added during 1 hour a mixture composed of 0.70parts of BPO and 10.0 parts of IPA. After this addition finished, themixture was furthermore maintained at the boiling point for 1 hour tocomplete a polymerization reaction, and then partially neutralized withan aqueous sodium hydroxide solution and treated with distillation toremove IPA, whereby whereby a water-soluble polymer (41) was obtained.Next, 380.0 parts of an aqueous solution of the water-soluble polymer(41) whose concentration was adjusted at 20% and 3.10 parts ofo-phthalic acid diglycidyl ester ("DENACOL EX-721", made by NAGASECHEMICALS Co., Ltd.) were added and maintained at the boiling point for3 hours to complete a reaction and then, completely neutralized with anaqueous sodium hydroxide solution, whereby a hydrophilic resin (43) wasobtained.

EXAMPLE 44

The procedure of example 43 was repeated except that 2.50 parts ofethylene glycol diglycidyl ether ("DENACOL EX-810", made by NAGASECHEMICALS Co., Ltd.) were added instead of o-phthalic acid diglycidylester in the example 43, whereby a hydrophilic resin (44) was obtained.

EXAMPLE 45

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed a mixture composed of 14.4 parts of 2-hydroxyethylmethacrylate, 3.2 parts of 2acrylamido-2-methylpropanesulfonic acid,14.4 parts of methacrylic acid, 1.14 parts of BPO, and 127.0 parts ofIPA and the inside atmosphere of the flask was replaced with stirring bynitrogen gas and the mixture was warmed up to the boiling point. Next,to this flask was added during 2 hours a mixture composed of 17.1 partsof 2-hydroxyethyl methacrylate, 3.8 parts of2-acrylamido-2-methylpropanesulfonic acid, 17.1 parts of methacrylicacid, 1.36 parts of BPO, and 150.9 parts of IPA and, after thoseaddition finished, were added during 1 hour a mixture composed of 0.83parts of BPO and 10.0 parts of IPA. After this addition finished, themixture was furthermore maintained at the boiling point for 1 hour tocomplete a polymerization reaction, and then partially neutralized withan aqueous sodium hydroxide solution and treated with distillation toremove IPA, whereby a water-soluble polymer (42) was obtained. Next,380.0 parts of an aqueous solution of the water-soluble polymer whoseconcentration was adjusted at 20% and 3.10 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)were added and maintained at the boiling point for 3 hours to complete areaction and then, completely neutralized with an aqueous sodiumhydroxide solution, whereby a hydrophilic resin (45 ) was obtained.

EXAMPLE 46

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 147.4 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 90° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 32.0 parts of 2-acrylamido-2-methylpropanesulfonicacid and 50.1 parts of water, a mixture solution composed of 48.0 partsof acrylic acid and 75.1 parts of water, and 31.6 parts of a 15% aqueousammonium persulfate solution during 2 hours and, after the additionfinished, were further added 15.8 parts of a 15% aqueous ammoniumpersulfate solution during 1 hour. After completion of the addition, themixture was further maintained at 90° C. for 1 hour to complete apolymerization reaction, whereby a water-soluble polymer (43) wasobtained. Next, to this were added 46.2 parts of water and 5.63 parts ofo-phthalic acid diglycidyl ester ("DENACOL EX-721", made by NAGASECHEMICALS Co., Ltd.) and the reaction mixture was maintained at theboiling point for 3 hours to complete a reaction and then, completelyneutralized with an aqueous sodium hydroxide solution, whereby ahydrophilic resin (46) was obtained.

EXAMPLE 47

The procedure of example 46 was repeated except that 5.02 parts ofadipic acid diglycidyl ester ("DENACOL EX-701", made by NAGASE CHEMICALSCo., Ltd.) were added instead of o-phthalic acid diglycidyl ester usedin the example 46, whereby a hydrophilic resin (47) was obtained.

EXAMPLE 48

The procedure of example 37 was repeated except that 5.6 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-841", made by NAGASECHEMICALS Co., Ltd.; an average mole number of added ethylene oxide isabout 13) were added instead of o-phthalic acid diglycidyl ester used inthe example 37, whereby a hydrophilic resin (48) was obtained.

EXAMPLE 49

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 164.2 parts of water and the inside atmosphere of the flaskwas replaced with stirring with nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. In this flask wereadded a mixture solution composed of 52.9 parts of methoxypolyethyleneglycol monomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICALCo., Ltd.; an average mole number of added ethylene oxide is 9), 10.0parts of 2-acrylamido-2-methylpropanesulfonic acid, 16.7 parts ofmethacylic acid, and 125.5 parts of water, and 24.6 parts of a 2.5%aqueous ammonium persulfate solution during 4 hours and, after theaddition finished, were further added 6.1 parts of a 2.5% aqueousammonium persulfate solution during 1 hour. After completion of theaddition, the reaction mixture was further maintained at the boilingpoint for 1 hour to complete a polymerization reaction, whereby awater-soluble polymer (44) was obtained. To this were added 3.2 parts ofo-phthalic acid diglycidyl ester ("DENACOL EX-721", made by NAGASECHEMICALS Co., Ltd.) and the mixture was maintained at the boiling pointfor 3 hours to complete a reaction and then, completely neutralized withan aqueous sodium hydroxide solution, whereby a hydrophilic resin (49)was obtained.

The average molecular weights (weight average) of the above-obtainedwater-soluble polymers were measured by GPC under said condition andresults obtained are shown in the Table 2.

Also, viscosity of the above-obtained hydrophilic resins were measuredsaid way and results obtained are shown in the Table 2.

EXAMPLE 50

Ordinary portland cement (made by Sumitomo Cement Co., Ltd.) was used ascement, river sand taken from Yodogawa as a a fine aggregate (specificgravity of 2.51 and a fineness modulas [F. M.] of 2.78), crashed stonefrom Takatsuki as a coarse aggregate (specific gravity of 2.68 and afineness modulas [F. M.] of 6.73), and the hydrophilic resin (37)obtained in the example 37 as a cement additive, and these materialswere respectively weighted to make 30 1 in amount of a kneaded mixturewith a composition of a unit ratio of 320 kg/m³ for cement, a unit ratioof 173 kg/m³ for water (a ratio of water to cement, 54.2%), a unit ratioof 934 kg/m³ for fine aggregate, a unit ratio of 876 kg/m³ for coarseaggregate (a fine aggregate percentage of 52%), and an addition amount0.23% of the hydrophilic resin (37) (a solid portion ratio against thecement), and then all the materials were placed into a tilting mixer.Immediately, the mixing and kneading were carried out for 3 minutes with35 r.p.m. of a rotation number, whereby a flowing concrete having anobject slump 18 cm and an object air amount 4.5% was prepared (in a caseof that the object air amount is not attained, a slight amount of anair-entraining agent [Vinsol], made by Yamaso Chemical Co., Ltd. wasused). A flowing concrete immediately after the mixing and kneading wassampled and the slump and air amount were measured.

After the mixing and kneading, the rotation number of the tiltingmixture was reduced to 3 r.p.m. and the mixing and kneading was furthercontinued and then, after 60 minutes, 90 minutes, and 120 minutes, theslump and air amount were measured to investigate their changes withtime-passage.

Also, the compressive strength and setting time of the flowing concreteobtained were measured. These measurement results are presented in Table2.

Besides, the measurement methods for the slump, air amount, compressivestrength, and setting time, and the method to take samples for testingthe compressive strength are based on the JIS A6204 (Japanese IndustrialStandard).

EXAMPLES 51 TO 62

The procedure of example 50 was repeated except that the hydrophilicresins (38) to (49) obtained from the examples 38 to 49 are used ascement additives in the amounts shown in Table 2, and the flowingconcretes thus-prepared were measured in the slump, air amount,compressive strength, and setting time. Results obtained are shown inTable 2.

Example for comparison 5

The procedure of example 50 was repeated except that the water-solublepolymer (37) obtained from the example 37 was used in an addition amountof 0.32% (against cement) as a cement additive instead of thehydrophilic resin (37), and a flowing concrete for comparisonthus-prepared was measured in the slump, air amount, compressivestrength, and setting time. Results obtained are shown in Table 2.

                                      TABLE 2                                     __________________________________________________________________________                                           The upper side: Slump (cm)                     Water-soluble                                                                          Cement admixture used The middle side: Air amount (%)                polymer              Addition amount                                                                         The under side: Residual % of                                                 slump(*3)                                         Molecular    Viscosity                                                                          (solid portion, %)                                                                      Immediately                                                                           after 60                                                                           after                                                                              after 120                    No.                                                                              weight(*1)   (cps)(*2)                                                                          (against cement)                                                                        after kneading                                                                        minutes                                                                            minutes                                                                            minutes              __________________________________________________________________________    Example 50                                                                            (37)                                                                             15,000                                                                              Hydrophilic                                                                          30.5 0.23      18.2    16.9 16.5 16.2                                  resin                 4.3     4.5  4.6  4.4                                   (37)                  --      93   91   89                   Example 51                                                                            (37)                                                                             15,000                                                                              Hydrophilic                                                                          2,790                                                                              0.24      17.8    18.0 18.2 17.6                                  resin                 5.0     4.6  4.8  4.6                                   (38)                  --      101  102  99                   Example 52                                                                            (37)                                                                             15,000                                                                              Hydrophilic                                                                          35.0 0.23      18.6    19.0 18.8 17.8                                  resin                 4.8     5.0  5.1  4.6                                   (39)                  --      102  101  96                   Example 53                                                                            (38)                                                                              6,600                                                                              Hydrophilic                                                                          14.3 0.18      18.4    18.3 17.8 17.2                                  resin                 4.8     5.0  5.0  4.5                                   (40)                  --      99   97   93                   Example 54                                                                            (39)                                                                             52,000                                                                              Hydrophilic                                                                          1,200                                                                              0.25      17.3    18.2 18.0 17.3                                  resin                 3.8     4.2  4.5  4.2                                   (41)                  --      105  104  100                  Example 55                                                                            (40)                                                                              8,000                                                                              Hydrophilic                                                                          7,800                                                                              0.33      19.4    18.0 17.5 17.0                                  resin                 5.2     4.3  4.3  4.1                                   (42)                  --      93   90   88                   Example 56                                                                            (41)                                                                             12,000                                                                              Hydrophilic                                                                          18.7 0.20      18.3    18.9 18.5 17.8                                  resin                 5.4     5.0  5.2  4.6                                   (43)                  --      103  101  97                   Example 57                                                                            (41)                                                                             12,000                                                                              Hydrophilic                                                                          17.2 0.20      18.6    17.9 15.1 11.5                                  resin                 4.7     4.5  4.3  4.1                                   (44)                  --      96   81   62                   Example 58                                                                            (42)                                                                              6,000                                                                              Hydrophilic                                                                          13.1 0.18      18.0    17.5 17.3 17.1                                  resin                 4.5     4.9  5.0  4.6                                   (45)                  --      97   96   95                   Example 59                                                                            (43)                                                                             17,000                                                                              Hydrophilic                                                                          34.2 0.21      19.0    17.2 17.5 17.0                                  resin                 4.2     4.5  4.7  4.3                                   (46)                  --      91   92   89                   Example 60                                                                            (43)                                                                             17,000                                                                              Hydrophilic                                                                          33.8 0.21      18.5    17.9 17.6 17.2                                  resin                 4.3     4.4  4.7  4.1                                   (47)                  --      97   95   93                   Example 61                                                                            (37)                                                                             15,000                                                                              Hydrophilic                                                                          35.4 0.35      17.8    17.2 14.8 12.1                                  resin                 4.1     4.1  3.8  3.7                                   (48)                  --      97   83   68                   Example 62                                                                            (44)                                                                             18,000                                                                              Hydrophilic                                                                          3,400                                                                              0.12      17.2    16.8 16.6 16.0                                  resin                 4.0     4.2  4.5  4.3                                   (49)                  --      98   97   93                   Example for                                                                           -- --    Water-solu-                                                                          --   0.32      18.9    7.0  --   --                   comparison 5     ble polymer           3.8     3.9  --   --                                    (37)                  --      37   --   --                   __________________________________________________________________________                                                    Condensation                                                                          Setting time                                                          strength                                                                              (hour:minute)                                                         age of 28                                                                             (beginning/                                                           days (kg/cm.sup.2)                                                                    finishing)            __________________________________________________________________________                                            Example 50                                                                            358     5:41/7:38                                                     Example 51                                                                            363     5:08/7:12                                                     Example 52                                                                            340     5:19/7:20                                                     Example 53                                                                            330     5:19/7:21                                                     Example 54                                                                            324     5:41/7:33                                                     Example 55                                                                            318     6:05/7:53                                                     Example 56                                                                            334     5:27/7:27                                                     Example 57                                                                            325     5:30/7:23                                                     Example 58                                                                            320     5:20/7:15                                                     Example 59                                                                            329     5:30/7:13                                                     Example 60                                                                            335     5:15/7:11                                                     Example 61                                                                            321     5:30/7:19                                                     Example 62                                                                            334     5:28/7:34                                                     Example for                                                                           303     6:53/9:05                                                     comparison 5                          __________________________________________________________________________     (*1)Measured by G.P.C.                                                        (*2)Measured by a B type rotational viscometer at 20° C. and 20%       ##STR18##                                                                

EXAMPLE 63

Into glass-made reaction vessel equipped with a thermometer, stirrer, adropping funnel, a gas-inlet tube, and a reflux condenser were placed37.2 parts of water and the inside atmosphere of the flask was replacedwith stirring by nitrogen gas and the flask was warmed up to 95° C.under the nitrogen atmosphere. To this were added a mixture solutioncomposed of 5 parts of sodium 2-sulfoethyl methacrylate, 15 parts ofacrylic acid, and 30 parts of water, and 8.5 parts of a 5% aqueousammonium persulfate solution during 2 hours and, after the additionfinished, were further added 4.3 parts of a 5% aqueous ammoniumpersulfate solution during 1 hour. After completion of the addition, themixture was further maintained at 95° C. for 1 hour to complete apolymerization reaction, whereby a water-soluble polymer (63) having anaverage molecular weight of 5200 was obtained.

Next, to this were added 1.0 part of o-phthalic acid diglycidyl ester("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and the reactionmixture was maintained at the boiling point for 3 hours to complete areaction and then, completely neutralized with an aqueous sodiumhydroxide solution, whereby a hydrophilic resin (63) was obtained.

EXAMPLE 64

The procedure of example 63 was repeated except that 1.0 part of adipicacid diglycidyl ester ("DENACOL EX-701", made by NAGASE CHEMICALS Co.,Ltd.) was added instead of o-phthalic acid diglycidyl ester used in theexample 63, whereby a hydrophilic resin (64) was obtained.

EXAMPLE 65

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 39.3 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 95° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 10 parts of sodium 2-sulfoethyl methacrylate, 10parts of acrylic acid, and 30 parts of water, and 1.1 parts of a 5%aqueous ammonium persulfate solution during 2 hours and, after theaddition finished, were further added 3.6 parts of a 5% aqueous ammoniumpersulfate solution during 1 hour. After completion of the addition, themixture was further maintained at 95° C. for 1 hour to complete apolymerization reaction, whereby a water-soluble polymer (64) having anaverage molecular weight of 4800 was obtained.

Next, to this were added 2.0 parts of o-phthalic acid diglycidyl ester("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and the reactionmixture was maintained at the boiling point for 3 hours to complete areaction and then, completely neutralized with an aqueous sodiumhydroxide solution, whereby a hydrophilic resin (68) was obtained.

EXAMPLE 66

The procedure of example 65 was repeated except that 2.0 parts ofpolyethylene glycol diglycidyl ether (an average mole number of addedethylene oxide is 9) ("DENACOL EX-832", made by NAGASE CHEMICALS Co.,Ltd.) was added instead of o-phthalic acid diglycidyl ester used in theexample 65, whereby a hydrophilic resin (66) was obtained.

EXAMPLE 67

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 37.2 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 95° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 5 parts of sodium 2-sulfoethyl methacrylate, 15parts of acrylic acid, and 30 parts of water, and 8.5 parts of a 2.3%aqueous ammonium persulfate solution during 2 hours and, after theaddition finished, were further added 4.3 parts of a 2.3% aqueousammonium persulfate solution during 1 hour. After completion of theaddition, the mixture was further maintained at 95° C. for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer (65)having an average molecular weight of 20000 was obtained.

Next, to this were added 1.0 part of o-phthalic acid diglycidyl ester("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and the reactionmixture was maintained at the boiling point for 3 hours to complete areaction and then, completely neutralized with an aqueous sodiumhydroxide solution, whereby a hydrophilic resin (67) was obtained.

EXAMPLE 68

The procedure of example 63 was repeated except that 1.2 parts of adipicacid diglycidyl ester ("DENACOL EX-701", made by NAGASE CHEMICALS Co.,Ltd.) was added instead of o-phthalic acid diglycidyl ester used in theexample 63, whereby a hydrophilic resin (68) was obtained.

EXAMPLE 69

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 42.8 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 95° C. under the nitrogen atmosphere. To this were added a mixturesolution composed of 12 parts of sodium 3-sulfopropoxyethylene glycolmonoacrylate, 8 parts of acrylic acid, and 30 parts of water, and 4.8parts of a 5% aqueous ammonium persulfate solution during 2 hours and,after the addition finished, were further added 2.4 parts of a 5%aqueous ammonium persulfate solution during 1 hour. After completion ofthe addition, the mixture was further maintained at 95° C. for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer (66)having an average molecular weight of 6500 was obtained.

Next, to this were added 1.0 part of o-phthalic acid diglycidyl ester("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and the reactionmixture was maintained at the boiling point for 3 hours to complete areaction and then, completely neutralized with an aqueous sodiumhydroxide solution, whereby a hydrophilic resin (69) was obtained.

EXAMPLE 70

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenser wasplaced a mixture composed of 14.4 parts of 2-hydroxyethyl methacrylate,3.2 parts of 2-sulfoethyl methacrylate, 14.4 parts of methacrylic acid,0.96 parts of BPO, and 127.0 parts of IPA and the inside atmosphere ofthe flask was replaced with stirring by nitrogen gas and the flask waswarmed up to the boiling point under the nitrogen atmosphere. Next, tothis was added a mixture composed of 17.1 parts of 2-hydroxyethylmethacrylate, 3.8 parts of 2-sulfoethyl methacrylate, 17.1 parts ofmethacrylic acid, 1.14 parts of BPO, and 150.9 parts of IPA during 2hours and, after the addition finished, was further added a mixturecomposed of 0.70 parts of BPO and 10.0 parts of IPA during 1 hour. Afterthe addition finished, the reaction mixture was maintained at theboiling point for 1 hour to complete a polymerization reaction,partially neutralized with an aqueous sodium hydroxide solution, andtreated with distillation to remove IPA, whereby a water-soluble polymer(67) was obtained. Next, 380.0 parts of an aqueous solution of thewater-soluble polymer (67) whose concentration was adjusted at 20% and3.10 parts of o-phthalic acid diglycidyl ester ("DENACOL EX-721", madeby NAGASE CHEMICALS Co., Ltd.) were added and maintained at the boilingpoint for 3 hours to complete reaction and then, completely neutralizedwith an aqueous sodium hydroxide solution, whereby a hydrophilic resin(70) was obtained.

EXAMPLE 71

The procedure of example 70 was repeated except that 2.50 parts ofethylene glycol diglycidyl ether ("DENACOL EX-810", made by NAGASECHEMICALS Co., Ltd.) was added instead of o-phthalic acid diglycidylester used in the example 70, whereby a hydrophilic resin (71) wasobtained.

EXAMPLE 72

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, gas-inlet tube, and a reflux condenser wasplaced a mixture composed of 14.4 parts of 2-hydroxyethyl methacrylate,3.2 parts of 2-sulfoethyl methacrylate, 14.4 parts of methacrylic acid,1.14 parts of BPO, and 127.0 parts of IPA and the inside atmosphere ofthe flask was replaced with stirring by nitrogen gas and the flask waswarmed up to the boiling point under the nitrogen atmosphere. Next, tothis was added a mixture composed of 17.1 parts of 2-hydroxyethylmethacrylate, 3.8 parts of sulfoethyl methacrylate, 17.1 parts ofmethacrylic acid, 1.36 parts of BPO, and 150.9 parts of IPA during 2hours and, after the addition finished, was further added a mixturecomposed of 0.83 parts of BPO and 10.0 parts of IPA during 1 hour. Afterthe addition finished, the reaction mixture was maintained at theboiling point for 1 hour to complete a polymerization reaction, thenpartially neutralized with an aqueous sodium hydroxide solution, andtreated with distillation to remove IPA, whereby a water-soluble polymer(68) was obtained. Next, 380.0 parts of an aqueous solution of thewater-soluble polymer (68) whose concentration was adjusted at 20% and3.10 parts of o-phthalic acid diglycidyl ester ("DENACOL EX-721", madeby NAGASE CHEMICALS Co., Ltd.) were added and maintained at the boilingpoint for 3 hours to complete a reaction and then, completelyneutralized with an aqueous sodium hydroxide solution, whereby ahydrophilic resin (72) was obtained.

EXAMPLE 73

The procedure of example 63 was repeated except that 1.0 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-841", made by NAGASECHEMICALS Co., Ltd.; an average mole number of added ethylene oxide isabout 13) were added instead of o-phthalic acid diglycidyl ester used inthe example 63, whereby a hydrophilic resin (73) was obtained.

The average molecular weights (weight average) of the above-obtainedwater-soluble polymers were measured by GPC under said condition andresults obtained are shown in Table 3.

Also, viscosity of the above-obtained hydrophilic resins was measured insaid way and results obtained are shown in Table 3.

EXAMPLE 74

Ordinary portland cement was used as cement (made by Sumitomo CementCo., Ltd.), river sand taken from Yodogawa as a fine aggregate (specificgravity of 2.51 and a fineness modulas [F. M.] of 2.78), crashed stonesfrom Takatsuki (specific gravity of 2.68 and a fineness modulas [F. M.]of 6.73) as a coarse aggregate, and the hydrophilic resin (63) obtainedfrom the example 63 as a cement additive, and these materials wererespectively weighted to make 30 1 in amount of a kneaded mixture with acomposition of a unit ratio of 320 kg/m³ for cement, a unit ratio of 173kg/m³ for water (a ratio of water to cement was 54.2%), a unit ratio of934 kg/m³ for fine aggregate, a unit ratio of 876 kg/m³ for coarseaggregate (a ratio of fine aggregate was 52%), and an addition amount0.23% (a ratio of the solid portion against cement) of the hydrophilicresin (63), and all the materials were placed into a tilting mixer.Immediately, the mixing and kneading were carried out for 3 minutes witha rotation number of 35 r.p.m., a flowing concrete having an objectslump of 18 cm and an object air amount of 4.5% was prepared (in a caseof that the object air amount is not attained, a slight amount of anair-entraining agent, [Vinsol] made by Yamaso Chemical Co., Ltd., wasused). An obtained flowing concrete immediately after the kneading wassampled and its slump and air amount were measured.

After the kneading finished, the rotational number of the tilting mixerwas reduced to 2 r.p.m., the kneading was further continued, and theslump and air amount after 60 minutes, 90 minutes, and 120 minutes weremeasured to investigate their changes with time-passage.

Also, the compressive strength and setting time of the flowing concreteobtained were measured. Results obtained are shown in Table 3.

Besides, the measurement methods of the slump, air amount, compressivestrength, and setting time and the method to take a sample for testingthe compressive strength are based on the Japanese Industrial standards(JIS A6204).

EXAMPLES 75 TO 84

The procedure of example 74 was repeated except that the hydrophilicresins (64) to (73) obtained from the examples 64 to 73 as shown inTable 3 were used as cement additives in the amounts for adding shown inTable 3, and flowing concretes thus-prepared were measured in the slump,air amount, compressive strength, and setting time. Results obtained areshown in Table 3.

Example for comparison 6

The procedure of example 74 was repeated except that the water-solublepolymer (63) obtained from the example 63 was used as a cement additivein amount of 0.32% (against cement) instead of the hydrophilic resin(63), and a flowing concrete for comparison thus-prepared was measuredin the slump, air amount, compressive strength, and setting time.Results obtained are shown in Table 3.

                                      TABLE 3                                     __________________________________________________________________________                                           The upper side: Slump (cm)                     Water-soluble                                                                          Cement admixture used The middle side: Air amount (%)                polymer              Addition amount                                                                         The under side: Residual % of                                                 slump(*3)                                         Molecular    Viscosity                                                                          (solid portion, %)                                                                      Immediately                                                                           after 60                                                                           after                                                                              after 120                    No.                                                                              weight(*1)   (cps)(*2)                                                                          (against cement)                                                                        after kneading                                                                        minutes                                                                            minutes                                                                            minutes              __________________________________________________________________________    Example 74                                                                            (63)                                                                              5,200                                                                              Hydrophilic                                                                          11.3 0.23      18.4    18.2 18.0 17.3                                  resin                 4.8     4.3  4.4  4.0                                   (63)                  --      99   98   94                   Example 75                                                                            (63)                                                                              5,200                                                                              Hydrophilic                                                                          12.5 0.23      18.8    18.5 18.2 17.5                                  resin                 4.7     4.5  4.7  4.4                                   (64)                  --      98   97   93                   Example 76                                                                            (64)                                                                              4,800                                                                              Hydrophilic                                                                          30.6 0.22      18.2    18.8 19.0 18.0                                  resin                 4.9     4.8  5.1  4.8                                   (65)                  --      103  104  99                   Example 77                                                                            (64)                                                                              4,800                                                                              Hydrophilic                                                                          35.0 0.25      18.9    17.8 15.8 12.1                                  resin                 4.7     4.4  4.5  4.1                                   (66)                  --      94   84   64                   Example 78                                                                            (65)                                                                             20,000                                                                              Hydrophilic                                                                          123  0.27      18.4    18.2 17.8 17.2                                  resin                 4.2     4.6  4.8  4.5                                   (67)                  --      99   97   93                   Example 79                                                                            (65)                                                                             20,000                                                                              Hydrophilic                                                                          20.1 0.23      18.2    18.5 18.0 17.0                                  resin                 4.6     4.9  4.9  4.3                                   (68)                  --      102  99   93                   Example 80                                                                            (66)                                                                              6,500                                                                              Hydrophilic                                                                          15.3 0.23      18.4    17.4 17.2 16.8                                  resin                 4.5     4.6  4.9  4.6                                   (69)                  --      95   93   91                   Example 81                                                                            (67)                                                                             12,500                                                                              Hydrophilic                                                                          18.7 0.20      18.9    18.6 18.5 17.8                                  resin                 4.9     4.4  4.6  4.2                                   (70)                  --      98   98   94                   Example 82                                                                            (67)                                                                             12,500                                                                              Hydrophilic                                                                          16.4 0.20      18.6    18.0 15.6 10.8                                  resin                 4.4     4.2  4.4  4.0                                   (71)                  --      97   84   58                   Example 83                                                                            (68)                                                                              6,300                                                                              Hydrophilic                                                                          13.1 0.18      18.0    17.6 17.1 16.8                                  resin                 4.3     4.8  4.9  4.7                                   (72)                  --      98   95   93                   Example 84                                                                            (63)                                                                              6,200                                                                              Hydrophilic                                                                          12.8 0.30      18.5    17.4 15.5 12.0                                  resin                 4.0     3.8  3.8  3.9                                   (73)                  --      94   84   65                   Example for                                                                           -- --    Water-solu-                                                                          --   0.14      18.6    8.0  --   --                   comparison 6     ble polymer           4.0     4.2  --   --                                    (63)                  --      43   --   --                   __________________________________________________________________________                                                    Condensation                                                                          Setting time                                                          strength                                                                              (hour:minute)                                                         age of 28                                                                             (beginning/                                                           days (kg/cm.sup.2)                                                                    finishing)            __________________________________________________________________________                                            Example 74                                                                            325     5:35/7:18                                                     Example 75                                                                            318     5:20/7:18                                                     Example 76                                                                            338     5:10/7:13                                                     Example 77                                                                            345     5:18/7:15                                                     Example 78                                                                            350     5:25/7:30                                                     Example 79                                                                            320     5:25/7:10                                                     Example 80                                                                            350     5:19/7:16                                                     Example 81                                                                            344     5:11/7:07                                                     Example 82                                                                            333     5:25/7:31                                                     Example 83                                                                            318     5:20/7:26                                                     Example 84                                                                            349     5:18/7:21                                                     Example for                                                                           301     5:50/7:58                                                     comparison 6                          __________________________________________________________________________     (*1)Measured by G.P.C.                                                        (*2)Measured by a B type rotational viscometer at 20° C. and 20%       ##STR19##                                                                

EXAMPLE 85

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas- inlet tube, and a reflux condenserwas placed 760.9 parts of IPA and the inside atmosphere of the flask wasreplaced with stirring by nitrogen gas and the flask was warmed up tothe boiling point under the nitrogen atmosphere. Next, to this wereadded a mixture solution composed of 48.0 parts of a compound having thestructure as below-pictured ("Kayarad R-526", made by Nippon Kayaku Co.,Ltd.), 278.0 parts of methoxypolyethylene glycol monomethacrylate("NK-ester M-9G", made by SHIN-NAKAMURA Chemical Co., Ltd.; an averagemole number of added ethylene oxide is 9), 108.2 parts of methacrylicacid, 15.1 parts of sodium methacrylate, and 624.2 parts of water, and151.7 parts of an aqueous 2.5% ammonium persulfate solution during 4hours and, after the addition finished, was further added 37.9 parts ofan aqueous 2.5% ammonium persulfate solution during 1 hour. After theaddition finished, the reaction mixture was maintained at the boilingpoint for 1 hour to complete a polymerization reaction, treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(85) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (85) was as shown in Table 4. ##STR20##

GPC of the copolymer (85) was measured and its eluding curve was shownin FIG. 3. To an aqueous solution of the copolymer (85) was added sodiumhydroxide to adjust pH at 12 while stirring at room temperature. The GPCafter stirring for 30 minutes and 120 minutes were measured. A GPCeluding curve after stirring for 30 minutes is shown in FIG. 4, and aGPC eluding curve after stirring for 120 minutes is shown in FIG. 5.

As shown in FIGS. 3-5, a material of high molecular weight having aeluding time of about 60 minutes decreased, and a portion in a eludingtime of about 80 minutes which has a cement dispersion characterincreased.

EXAMPLE 86

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 836.5 parts of IPA and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wasadded a mixture solution composed of 48.0 parts of a compound used inthe example 85 ("Kayarad R-526", made by Nippon Kayaku Co., Ltd.), 278.0parts of methoxypolyethylene glycol monomethacrylate ("NK-ester M-9G",made by SHIN-NAKAMURA Chemical Co., Ltd.; an average mole number ofadded ethylene oxide is 9), 108.2 parts of methacrylic acid, 15.1 partsof sodium methacrylate, and 624.2 parts of water, and furthermore, wereadded 91.2 parts of an aqueous 2.5% ammonium persulfate solution during4 hours and, after the addition finished, was further added 22.8 partsof an aqueous 2.5% ammonium persulfate solution during 1 hour. After theaddition finished, the reaction mixture was maintained at the boilingpoint for 1 hour to complete a polymerization reaction, treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(86) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (86) was as shown in Table 4.

EXAMPLE 87

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenser wasplaced 760.9 parts of IPA and the inside atmosphere of the flask wasreplaced with stirring by nitrogen gas and the flask was warmed up tothe boiling point under the nitrogen atmosphere. Next, to this was addeda mixture solution composed of 48.0 parts of a compound having thestructure below-pictured ("Kayarad Manda", made by Nippon Kayaku Co.,Ltd.), 278.0 parts of methoxypolyethylene glycol monomethacrylate("NK-ester M-9G", made by SHIN-NAKAMURA Chemical Co., Ltd.; an averagemole number of added ethylene oxide is 9), 108.2 parts of methacrylicacid, 15.1 parts of sodium methacrylate, and 624.2 parts of water, andfurthermore, were added 151.7 parts of an aqueous 2.5% ammoniumpersulfate solution during 4 hours and, after the addition finished, wasfurther added 37.9 parts of an aqueous 2.5% ammonium persulfate solutionduring 1 hour. After the addition finished, the reaction mixture wasmaintained at the boiling point for 1 hour to complete a polymerizationreaction, treated with distillation to remove IPA, and completelyneutralized with an aqueous sodium hydroxide solution, whereby anaqueous solution of a copolymer (87) was obtained. The viscosity of a20% aqueous solution of this copolymer (87) was as shown in Table 4.##STR21##

EXAMPLE 88

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 760.9 parts of IPA and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wasadded a mixture solution composed of 48.0 parts of a compound having thestructure below-pictured ("Kayarad HX-220", made by Nippon Kayaku Co.,Ltd.), 278.0 parts of methoxypolyethylene glycol monomethacrylate("NK-ester M-9G", made by SHIN-NAKAMURA Chemical Co., Ltd.; an averagemole number of added ethylene oxide is 9), 108.2 parts of methacrylicacid, 15.1 parts of sodium methacrylate, and 624.2 parts of water, and151.7 parts of an aqueous 2.5% ammonium persulfate solution during 4hours and, after the addition finished, was further added 37.9 parts ofan aqueous 2.5% ammonium persulfate solution during 1 hour. After theaddition finished, the reaction mixture was maintained at the boilingpoint for 1 hour to complete a polymerization reaction, treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(88) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (88) was as shown in Table 4. ##STR22##

EXAMPLE 89

Into glass-made reaction vessel equipped with a thermometer, a stirrer,a dropping funnel, a gas-inlet tube, and a reflux condenser were placed760.9 parts of IPA and the inside atmosphere of the flask was replacedwith stirring by nitrogen gas and the flask was warmed up to the boilingpoint under the nitrogen atmosphere. Next, to this was added a mixturesolution composed of 48.0 parts of a compound having the structurebelow-pictured ("Kayarad DPCA-20", made by Nippon Kayaku Co., Ltd.),278.0 parts of methoxypolyethylene glycol monomethacrylate ("NK-esterM-9G", made by SHIN-NAKAMURA Chemical Co., Ltd.; an average mole numberof added ethylene oxide is 9), 108.2 parts of methacrylic acid, 15.1parts of sodium methacrylate, and 624.2 parts of water, and furthermore,were added 151.7 parts of an aqueous 2.5% ammonium persulfate solutionduring 4 hours and, after the addition finished, was further added 37.9parts of an aqueous 2.5% ammonium persulfate solution during 1 hour.After the addition finished, the reaction mixture was maintained at theboiling point for 1 hour to complete a polymerization reaction, treatedwith distillation to remove IPA, and completely neutralized with anaqueous sodium hydroxide solution, whereby an aqueous solution of acopolymer (89) was obtained. The viscosity of a 20% aqueous solution ofthis copolymer (89) was as shown in Table 4. ##STR23##

EXAMPLE 90

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 797.0 parts of IPA and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wasadded a mixture solution composed of 48.0 parts of the compound used inthe example 88 ("Kayarad HX-220", made by Nippon Kayaku Co., Ltd.),314.5 parts of methoxypolyethylene glycol monomethacrylate ("NK-esterM-9G", made by SHIN-NAKAMURA Co., Ltd.; an average mole number of addedethylene oxide is 9), 75.0 parts of methacrylic acid, 10.5 parts ofsodium methacrylate, and 625.5 parts of water, and furthermore, wereadded 122.8 parts of an aqueous 2.5% ammonium persulfate solution during4 hours and, after the addition finished, was further added 30.7 partsof an aqueous 2.5% ammonium persulfate solution during 1 hour. After theaddition finished, the reaction mixture was maintained at the boilingpoint for 1 hour to complete a polymerization reaction, treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(90) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (90) was as shown in Table 4.

EXAMPLE 91

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 164.2 parts of IPA and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wasadded a mixture solution composed of 9.6 parts of a compound used in theexample 85 ("Kayarad R-526", made by Nippon Kayaku Co., Ltd.), 62.9parts of polyethylene glycol polypropylene glycol methacrylate ("Blenmer70PEP-350B", made by NIPPON OIL & FATS Co., Ltd.; an average mole numberof added ethylene oxide is 7 and that of added propylene oxide is 3),16.7 parts of methacrylic acid, and 125.5 parts of water, andfurthermore, were added 24.6 parts of an aqueous 2.5% ammoniumpersulfate solution during 4 hours and, after the addition finished, wasfurther added 6.1 parts of an aqueous 2.5% ammonium persulfate solutionduring 1 hour. After the addition finished, the reaction mixture wasmaintained at the boiling point for 1 hour to complete a polymerizationreaction, treated with distillation to remove IPA, and completelyneutralized with an aqueous sodium hydroxide solution, whereby anaqueous solution of a copolymer (91) was obtained. The viscosity of a20% aqueous solution of this copolymer (91) was as shown in Table 4.

EXAMPLE 92

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 760.9 parts of IPA and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wasadded a mixture solution composed of 48.0 parts of a compound used inthe example 85 ("Kayarad R-526", made by Nippon Kayaku Co., Ltd.), 278.0parts of methoxypolyethylene glycol monomethacrylate ("NK-ester M-23G",made by SHIN-NAKAMURA CHEMICAL Co., Ltd.; an average mole number ofadded ethylene oxide is 23), 108.2 parts of methacrylic acid, 15.1 partsof sodium methacrylate, and 624.2 parts of water, and 151.7 parts of anaqueous 2.5% ammonium persulfate solution during 4 hours and, after theaddition finished, was further added 37.9 parts of an aqueous 2.5%ammonium persulfate solution during 1 hour. After the addition finished,the reaction mixture was maintained at the boiling point for 1 hour tocomplete a polymerization reaction, treated with distillation to removeIPA, and completely neutralized with an aqueous sodium hydroxidesolution, whereby an aqueous solution of a copolymer (92) was obtained.The viscosity of a 20% aqueous solution of this copolymer (92) was asshown in Table 4.

EXAMPLE 93

The procedure of example 85 was repeated except that the compound usedin the example 85 ("Kayarad R-526", made by Nippon Kayaku Co., Ltd.) was72.0 parts in amount, whereby a copolymer (93) was obtained. Theviscosity of a 20% aqueous solution of this copolymer (93) is as shownin Table 4.

EXAMPLE 94

The procedure of example 85 was repeated except that the compound usedin the example 85 ("Kayarad R-526", made by Nippon Kayaku Co., Ltd.) was24.0 parts in amount, whereby a copolymer (94) was obtained. Theviscosity of a 20% aqueous solution of this copolymer (94) is as shownin Table 4.

EXAMPLE 95

The procedure of example 85 was repeated except that 108.2 parts ofacrylic acid were used instead of methacrylic acid used in the example85 and 15.1 parts of sodium acrylate instead of sodium methacrylate,whereby a copolymer (95) was obtained. The viscosity of a 20% aqueoussolution of this copolymer (95) is as shown in Table 4.

EXAMPLE 96

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenser wasplaced a mixture composed of 4.00 g of a compound used in the example 85("Kayarad R-526", made by Nippon Kayaku Co., Ltd.), 17.6 parts of HEMA,14.4 parts of methacrylic acid, 1.0 part of BPO, and 127.0 parts of IPA,and the inside atmosphere of the flask was replaced with stirring bynitrogen gas and the flask was warmed up to the boiling point under thenitrogen atmosphere. Next, to this mixture was added a mixture composedof 4.66 parts of a compound used in the example 85 ("Kayarad R-526",made by Nippon Kayaku Co., Ltd.), 20.9 parts of HEMA, 17.1 parts ofmethacrylic acid, 1.1 parts of BPO, and 150.9 parts of IPA during 2hours and, after the addition finished, were further added 10. 7 partsof a 7% IPA solution of BPO during 1 hour. After the addition finished,the reaction mixture was maintained at the boiling point for 1 hour tocomplete a polymerization reaction, treated with distillation to removeIPA, and completely neutralized with an aqueous sodium hydroxidesolution, whereby an aqueous solution of a copolymer (96) was obtained.The viscosity of a 20 % aqueous solution of this copolymer (96) was asshown in Table 4.

Example for comparison 7

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 390.0 parts of IPA and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wasadded a mixture solution composed of 133.0 parts of methoxypolyethyleneglycol monomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICALCo., Ltd.; an average mole number of added ethylene oxide is 9), 27.0parts of methacrylic acid, 2.4 parts of BPO, and 240.0 parts of IPAduring 2 hours and, after the addition finished, were further added 10.5parts of a 4.9% BPO solution during 1 hour. After the addition finished,the reaction mixture was maintained at the boiling point for 2 hours tocomplete a polymerization reaction, treated with distillation to removeIPA, and completely neutralized with an aqueous sodium hydroxidesolution, whereby an aqueous solution of a copolymer for comparison (1)was obtained. The viscosity of a 20% aqueous solution of this copolymerfor comparison (1) was as shown in Table 4.

EXAMPLE 97

Ordinary portland cement was used as cement (made by Sumitomo CementCo., Ltd.), river sand taken from Yodogawa as a fine aggregate (specificgravity of 2.51 and a fineness modulas [F. M.] of 2.78), crashed stonesfrom Takatsuki (specific gravity of 2.68 and fineness modulas [F. M.] of6.73) as a coarse aggregate, and the copolymer (1) obtained from theexample 85 as a cement additive, and these materials were respectivelyweighted to make 30 1 in amount of a kneaded mixture with a compositionof a unit ratio of 320 kg/m ³ for cement, a unit ratio of 173 kg/m³ forwater (a ratio of water to cement was 54.2%), a unit ratio of 934 kg/m³for fine aggregate, a unit ratio of 876 kg/m³ for coarse aggregate (aratio of fine aggregate was 52% ), and an addition amount 0.10 (a ratioof the solid portion against cement) of the copolymer (85), which is acement additive, and then all the materials were placed into a tiltingmixer. Immediately, the mixing and kneading were carried out with arotation number of 35 r.p.m. for 3 minutes, a flowing concrete having anobject slump of 18 cm and an object air amount of 4.5% was prepared (ina case of that the object air amount not attained, a slight amount of anair-entraining agent, [Vinsol] made by Yamaso Chemical Co., Ltd., wasused). An obtained flowing concrete immediately after the kneading wassampled and its slump and air amount were measured.

After the kneading finished, the rotational number of the tilting mixerwas reduced to 3 r.p.m., the kneading was further continued, and theslump and air amount after 60 minutes, 90 minutes, and 120 minutes weremeasured to investigate their changes with time-passage.

Also, the compressive strength and setting time of the flowing concreteobtained were measured. Results obtained are shown in Table 4.

Besides, the measurement methods of the slump, air amount, compressivestrength, and setting time and the method to take a sample for testingthe compressive strength are based on the Japanese Industrial standards(JIS A6204).

EXAMPLES 98 TO 108

The procedure of example 97 was repeated except that the copolymers (86)to (96) obtained from the examples 86 to 96 as shown in Table 4 wereused as cement additives in the amounts for adding shown in Table 4, andflowing concretes thus-prepared were measured in the slump, air amount,compressive strength, and setting time. Results obtained are shown inTable 4.

EXAMPLE 109

The procedure of example 97 was repeated except that the copolymer (85)obtained from the example 85 and the copolymer for comparison (1)obtained from the example for comparison 7 were used as cement additivesin the amounts for adding shown in Table 4, and a flowing concretethus-prepared was measured in the slump, air amount, compressivestrength, and setting time. Results obtained are shown in Table 4.

EXAMPLE 110

The procedure of example 97 was repeated except that the copolymer (85)obtained from the example 85 and a sodium naphthalenesulfonate-formalincondensation product were used as cement additives in the amounts foradding shown in Table 4, and a flowing concrete thus-obtained wasmeasured in the slump, air amount, compressive strength, and settingtime. Results obtained are shown in Table 4.

EXAMPLE 111

The procedure of example 97 was repeated except that the copolymer (85)obtained from the example 85 and sodium ligninsulfonate were used ascement additives in the amounts for adding shown in Table 4, and aflowing concrete thus-obtained was measured in the slump, air amount,compressive strength, and setting time. Results obtained are shown inTable 4.

Example for comparison 8

The procedure of example 97 was repeated except that the copolymer forcomparison (1) obtained from the example for comparison 7 was used as acement additive in an amount of 0.10% (against cement) instead of thecopolymer (85), and a flowing concrete for comparison thus-prepared wasmeasured in the slump, air amount, compressive strength, and settingtime. Results obtained are shown in Table 4.

                                      TABLE 4                                     __________________________________________________________________________                                      The upper side: Slump (cm)                         Cement admixture used      The middle side: Air amount (%)                                      Addition amount                                                                        The under side: Residual % of                                                 slump(*3)                                                  Viscosity (cps)(*2)                                                                     (solid portion, %)                                                                     Immediately                                                                           after 60                                                                           after 90                                                                           after 120                                20° C.                                                                      25° C.                                                                      (against cement)                                                                       after kneading                                                                        minutes                                                                            minutes                                                                            minutes                   __________________________________________________________________________    Example 97                                                                           Copolymer                                                                             83.2 77.5 0.10     17.8    18.9 18.5 17.3                             (85)                       5.2     5.0  5.1  4.9                                                         --      106  104  97                        Example 98                                                                           Copolymer                                                                             290  260  0.10     16.8    18.0 18.2 17.0                             (86)                       4.9     4.8  4.9  4.7                                                         --      107  108  101                       Example 99                                                                           Copolymer                                                                             71.3 68.2 0.12     18.4    18.3 18.0 17.8                             (87)                       4.5     4.8  4.7  4.4                                                         --      99   98   97                        Example 100                                                                          Copolymer                                                                             90.8 80.4 0.10     18.8    18.6 18.2 17.6                             (88)                       4.9     4.3  4.2  4.0                                                         --      99   97   94                        Example 101                                                                          Copolymer                                                                             129  103  0.10     17.8    17.9 18.0 17.6                             (89)                       5.2     5.0  4.8  4.4                                                         --      101  101  99                        Example 102                                                                          Copolymer                                                                             60.3 54.8 0.10     18.3    17.2 17.2 17.0                             (90)                       5.0     4.8  4.7  4.3                                                         --      94   94   93                        Example 103                                                                          Copolymer                                                                             82.1 74.5 0.08     18.5    18.8 18.6 18.0                             (91)                       4.9     4.5  4.4  4.0                                                         --      102  101  97                        Example 104                                                                          Copolymer                                                                             103  94.8 0.14     18.2    19.0 19.0 18.5                             (92)                       4.3     4.5  4.7  4.6                                                         --      104  104  102                       Example 105                                                                          Copolymer                                                                             140  121.0                                                                              0.14     17.3    19.4 19.0 18.5                             (93)                       4.8     4.9  5.1  5.0                                                         --      112  110  107                       Example 106                                                                          Copolymer                                                                             46.3 41.5 0.10     18.5    18.0 17.5 17.0                             (94)                       4.1     4.3  4.2  3.9                                                         --      97   95   92                        Example 107                                                                          Copolymer                                                                             68.4 63.7 0.11     17.5    18.0 17.8 17.0                             (95)                       4.4     5.0  5.1  4.5                                                         --      103  102  97                        Example 108                                                                          Copolymer                                                                             61.4 58.4 0.23     17.8    18.8 18.7 17.9                             (96)                       3.8     4.0  4.4  4.0                                                         --      106  105  101                       Example 109                                                                          Copolymer (85)                                                                        --   --   0.05 + 0.05                                                                            19.1    18.8 18.0 17.2                             + Copolymer                4.6     4.5  4.4  4.0                              for compari-               --      98   94   90                               son (1)                                                                Example 110                                                                          Copolymer (85)                                                                        --   --   0.05 + 0.16                                                                            18.3    18.5 17.8 17.0                             + NSFZ(*4)                 4.2     4.4  4.0  4.0                                                         --      101  97   93                        Example 111                                                                          Copolymer (85)                                                                        --   --   0.05 + 0.16                                                                            17.9    18.3 17.8 17.1                             + LS(*5)                   4.0     4.1  4.2  4.0                                                         --      102  99   96                        Example for                                                                          Copolymer                                                                             25.0 23.1 0.10     18.2    13.4 --   --                        comparison                                                                           for compari-               4.0     4.5  --   --                        8      son (1)                    --      74   --   --                        __________________________________________________________________________                                     Condensation                                                                          Setting time                                                                          Molecular                                                     strength at                                                                           (hour:minute)                                                                         weight after                                                  age of 28                                                                             (beginning/                                                                           hydrolysis of                                                 days (kg/cm.sup.2)                                                                    finishing)                                                                            copolymer(*1)                __________________________________________________________________________                              Example 97                                                                           323     5:18/7:30                                                                             20,000                                                 Example 98                                                                           340     5:25/7:29                                                                             35,000                                                 Example 99                                                                           338     5:09/7:13                                                                             18,000                                                 Example 100                                                                          325     5:15/7:20                                                                             24,000                                                 Example 101                                                                          320     5:13/7:12                                                                             28,000                                                 Example 102                                                                          331     5:21/7:25                                                                             12,000                                                 Example 103                                                                          343     5:26/7:18                                                                             21,000                                                 Example 104                                                                          329     5:25/7:28                                                                             26,000                                                 Example 105                                                                          340     5:13/7:24                                                                             20,000                                                 Example 106                                                                          333     5:11/7:29                                                                             20,000                                                 Example 107                                                                          319     5:19/7:15                                                                             18,000                                                 Example 108                                                                          324     5:10/7:11                                                                             12,000                                                 Example 109                                                                          330     5:18/7:25                                                                             --                                                     Example 110                                                                          319     5:12/7:13                                                                             --                                                     Example 111                                                                          327     5:20/7:18                                                                             --                                                     Example for                                                                          330     5:28/7:21                                                                             --                                                     comparison 8                                        __________________________________________________________________________     (*1)Measured by G.P.C.                                                        (*2)Measured by a B type rotational viscometer at 20° C. and           25° C. and 20%                                                         ##STR24##                                                                     (*4)NSF: Sodium naphthalenesulfonateformalin condensation product             (*5)LS: Sodium ligninsulfonate                                           

EXAMPLE 112

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 707.5 parts of water and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. To this were added200.0 parts of a 80% aqueous acrylic acid solution and 195.6 parts of a5% aqueous sodium persulfate solution during 4 hours. After completionof the addition, the mixture was further maintained at the boiling pointfor 1 hour to complete a polymerization reaction and partiallyneutralized with an aqueous sodium hydroxide solution, whereby awater-soluble polymer (112) having an average molecular weight of 4000was obtained. Next, after water was distilled off, to 536.3 parts of anaqueous solution of the water-soluble polymer (112), whose concentrationwas adjusted at 40%, were added 17.2 parts of a compound used in theexample 16 ("DENACOL EX-202", made by NAGASE CHEMICALS Co., Ltd.) andthe reaction mixture was maintained at the boiling point for 3 hours tocomplete a reaction and then, completely neutralized with an aqueoussodium hydroxide solution, whereby a hydrophilic resin (112) wasobtained.

EXAMPLE 113

The procedure of example 112 was repeated except that 10.7 parts ofpolyethylene glycol diglycidyl ether ("DENACOL EX-841", made by NAGASECHEMICALS Co., Ltd.) was added instead of the compound used in theexample 16, whereby a hydrophilic resin (113) was obtained.

EXAMPLE 114

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a nitrogen gas-inlet tube, and a refluxcondenser were placed 300 parts of water and the inside atmosphere ofthe flask was replaced with stirring by nitrogen gas and the flask waswarmed up to 95° C. under the nitrogen atmosphere.

Next, to this were added during 2 hours a monomer solution composed of107.7 parts of a quarternary salt of N,N-dimethylaminoethyl methacrylateand 100.0 parts of water, a monomer solution composed of 52.3 parts ofsodium acrylate, and 162.2 parts of water, and 77.8 parts of a 5%aqueous ammonium persulfate solution, respectively. After completion ofthe addition, the mixture was further maintained at 95° C. for 1 hour tocomplete a polymerization reaction, whereby a water-soluble polymer(113) having an average molecular weight of 28000 was obtained.

Next, to this were added 12.8 parts of o-phthalic acid diglycidyl ester("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and the reactionmixture was maintained at the boiling point for 3 hours to complete areaction, whereby a hydrophilic resin (114) was obtained.

EXAMPLE 115

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 378.9 parts of polyalkyleneglycol monoallyl ether (anaverage mole number of added ethylene oxide is 10) and 188.5 parts ofwater, and the inside atmosphere of the flask was replaced with stirringby nitrogen gas and the flask was warmed up to 95° C. under the nitrogenatmosphere. Next, to this was added a mixture solution composed of 88.2parts of maleic acid, 14 parts of ammonium persulfate, and 132.3 partsof water during 120 minutes and, after the addition finished, werefurther added 14 parts of a 20% aqueous ammonium persulfate solutionduring 20 minutes. After the addition finished, the reaction mixture wasmaintained at 95° C. for 100 minutes to complete a polymerizationreaction and then, partially neutralized with an 40% aqueous sodiumhydroxide solution, whereby a water-soluble polymer (114) having anaverage molecular weight of 3000 was obtained.

Next, to this polymer were added 28.4 parts of the compound used in theexample 16 ("DENACOL EX-202", made by NAGASE CHEMICALS Co., Ltd.) andthe mixture was maintained at the boiling point for 3 hours to completea reaction and then, completely neutralized with an aqueous sodiumhydroxide solution, whereby a hydrophilic resin (115) was obtained.

EXAMPLE 116

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a nitrogen gas-inlet tube, and a refluxcondenser were placed 30 parts of polyethyleneglycol monoallyl ether (anaverage mole number of ethylene oxide added is 10) and 475 parts ofwater, and the inside atmosphere of the flask was replaced with stirringby nitrogen gas and the flask was warmed up to 95° C. under the nitrogenatmosphere. Next, to this were added during 120 minutes 447 parts of a38% aqueous sodium acrylate solution and 40 parts of a 5% aqueousammonium persulfate solution, respectively. After the addition finished,were further added 8 parts of a 5% aqueous ammonium persulfate solutionduring 20 minutes. After this addition finished, the reaction mixturewas maintained at 95° C. for 120 minutes to complete a polymerizationreaction, whereby a water-soluble polymer (115) having an averagemolecular weight of 5200 was obtained.

Next, to this polymer were added 20.0 parts of the compound used in theexample 16 ("DENACOL EX-202", made by NAGASE CHEMICALS Co., Ltd.) andthe mixture was maintained at the boiling point for 3 hours to completea reaction, whereby a hydrophilic resin (116) was obtained.

EXAMPLE 117

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 60 parts of polyethyleneglycol monoallyl ether (an averagemole number of ethylene oxide added is 30) and 524 parts of water, andthe inside atmosphere of the flask was replaced with stirring bynitrogen gas and the flask was warmed up to 95° C. under the nitrogenatmosphere. Next, to this were added during 120 minutes 368 parts of 38%sodium methacrylate and 40 parts of a 5% aqueous ammonium persulfatesolution, respectively. After the addition finished, was further added 8parts of a 5% aqueous ammonium persulfate solution during 20 minutes.After this addition finished, the reaction mixture was maintained at 95°C. for 120 minutes to complete a polymerization reaction, whereby awater-soluble polymer (116) having an average molecular weight of 18000was obtained.

Next, to this polymer were added 20.0 parts of the compound used in theexample 16 ("DENACOL EX-202", made by NAGASE CHEMICALS Co., Ltd.) andthe mixture was maintained at the boiling point for 3 hours to completea reaction, whereby a hydrophilic resin (117) was obtained.

EXAMPLE 118

The procedure of example 117 was repeated except that 20.0 parts ofpolyethyleneglycol diglycidyl ether ("DENACOL EX-830", made by NAGASECHEMICALS Co., Ltd.) was added instead of the compound used the example16, whereby a hydrophilic resin (118) was obtained.

EXAMPLE 119

Into a glass-made reaction vessel equipped with a thermometer, astirrer, three dropping funnels, a gas-inlet tube, and a refluxcondenser were placed 801.2 parts of water, and the inside atmosphere ofthe flask was replaced with stirring by nitrogen gas and the flask waswarmed up to 95° C. under the nitrogen atmosphere. Next, to this wereadded a mixture composed of 314.4 parts of acrylic acid, 45.6 parts ofsodium acrylate, and 360 parts of water, a mixture composed of 11.1parts of ammonium persulfate and 99.6 parts of water, and a mixturecomposed of 50.5 parts of sodium hydrogen sulfite and 117.7 parts ofwater during 240 minutes through the individual funnels. After theaddition finished, the reaction mixture was maintained at 95° C. for 60minutes to complete a polymerization reaction.

Next, a polymerization product obtained was cooled to 40° C., to which166.7 parts of ethyleneimine were added during 1 hour. After theaddition finished, the reaction mixture was warmed up to 90° C. andmaintained at this temperature for 120 minutes to complete an additionreaction, whereby a water-soluble polymer (117) was obtained. Theaminoethylated percentage of this polymer (117) was measured withquantitative determination of unreacting carboxyl groups by conductivitytitration and the result indicated that the reacting mole number ofethyleneimine per one mole carboxyl group in this polymer was 0.8.

Next, to this polymer were added 35.3 parts of the compound used in theexample 16 ("DENACOL EX-202", made by NAGASE CHEMICALS Co., Ltd.) andthe mixture was maintained at the boiling point for 3 hours to completea reaction, whereby hydrophilic resin (119) was obtained.

EXAMPLE 120

Into a glass-made reaction vessel equipped with a thermometer, astirrer, three dropping funnels, a gas-inlet tube, and a refluxcondenser were placed 278.6 parts of water, and the inside atmosphere ofthe flask was replaced with stirring by nitrogen gas and the flask waswarmed up to 95° C. under the nitrogen atmosphere. Next, to this wereadded a mixture composed of 160 parts of methacrylic acid and 240 partsof water and a mixture composed of 12.1 parts of ammonium persulfate and68.8 parts of water during 120 minutes, respectively. Subsequently, amixture composed of 6.1 parts of ammonium persulfate and 34.4 parts ofwater was added during 60 minutes. After the addition finished, thereaction mixture was maintained at 95° C. for 60 minutes to complete apolymerization reaction.

Next, a polymerization product obtained was cooled to 30° C., to which255.6 parts of water were added, and the mixture was warmed up to 40°C., to which 63.9 parts of ethyleneimine were added during 1 hour. Afterthe addition finished, the reaction mixture was warmed up to 90° C. andmaintained at this temperature for 120 minutes to complete an additionreaction, whereby an aqueous solution of a water-soluble polymer (118)was obtained. The aminoethylated percentage of this polymer (118) wasmeasured with quantitative determination of unreacting carboxyl groupsby conductivity titration and the result indicated that the reactingmole number of ethyleneimine per one mole carboxyl group in this polymerwas 0.8.

Next, to this polymer were added 15.43 parts of the compound used in theexample 16 ("DENACOL EX-202", made by NAGASE CHEMICALS Co., Ltd.) andthe mixture was maintained at the boiling point for 3 hours to completea reaction, whereby a hydrophilic resin (120) was obtained.

EXAMPLE 121

Into a steel-made autoclave equipped with a thermometer, a stirrer, apressure meter, and two gas-inlet tubes were placed 89 parts of maleicanhydride, 15.0 parts of BPO, and 875 parts of dichloroethane, theinside air of the autoclave was sufficiently replaced with stirring byethylene gas by repeatedly applying a pressure and withdrawing it with10 kg/cm² of ethylene, and a polymerization reaction was carried out at70° C. during 10 hours keeping a pressure of 20 to 30 kg/cm² withfurther addition of ethylene. A reactione product was taken out easilywith filtration and dried under vacuum, whereby 95.1 parts of a polymerhaving carboxyl group was obtained.

The composition ratio of maleic anhydride to ethylene in the polymerhaving a carboxyl group thus-obtained was determined by titrationanalysis with an aqueous sodium hydroxide solution and an analysisresult indicated a 29:71 mole ratio of maleic anhydride to ethylene. Inaddition, a number average molecular weight of the polymer having acarboxyl group was shown as 21,000 with high performance liquidchromatography.

Next, into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 95.1 parts of the polymer having a carboxyl group and 403.2parts of water, and the inside atmosphere of the flask was replaced withstirring by nitrogen gas and the flask was warmed at 80° C. for 2 hoursunder the nitrogen atmosphere, whereby an aqueous solution of thepolymer having a carboxyl group was obtained. Next, this aqueoussolution was cooled to 40° C. and to this solution were added 39.3 partsof ethylenimine during 1 hour while maintaining the temperature at 40°C. After the addition finished, the reaction mixture was warmed up to90° C. and maintained at this temperature for 120 minutes to complete anaddition reaction, whereby an aqueous solution of a water-solublepolymer (119) was obtained.

The aminoethylated percentage of this polymer (119) was measured withquantitative determination of unreacting carboxyl groups by conductivitytitration and the result indicated that the reacting mole number ofethyleneimine per one mole carboxyl group in this polymer (119) was 0.8.Next, to this polymer were added 8.1 parts of o-phthalic acid diglycidylester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and themixture was maintained at the boiling point for 3 hours to complete areaction, whereby a hydrophilic resin (121) was obtained.

EXAMPLE 122

Into the same glass-made reaction vessel as used for the example 121were placed 136.3 parts of maleic anhydride and 221.3 parts of methylethyl ketone, and the inside atmosphere of the flask was replaced withstirring by nitrogen gas and the flask was warmed up to 92° C. under thenitrogen atmosphere. Next, to this were added a mixture composed of144.9 parts of styrene and 144.9 parts of methyl ethyl ketone and amixture composed of 13.9 parts of BPO and 55.6 parts of methyl ethylketone during 120 minutes. After addition finished, the reaction mixturewas maintained at 92° C. for 60 minutes to complete a polymerizationreaction and, then evaporated, whereby 280.7 parts of a polymer having acarboxyl group was obtained.

The number average molecular weight of the polymer having a carboxylgroup thus-obtained was measured as 35,000.

Next, into the same glass-made reaction vessel as used above were placed280.7 parts of the polymer having a carboxyl group and 1076 parts ofwater, and the inside atmosphere of the flask was replaced with stirringby nitrogen gas and the flask was warmed up to 40° C. under the nitrogenatmosphere. Next, while maintaining at this temperature, to this flaskwere added 78.0 parts of ethyleneimine during 1 hour. After additionfinished, the reaction mixture was warmed up to 90° C. and maintained atthis temperature for 120 minutes to complete an addition reaction,whereby an aqueous solution of a water-soluble polymer (120) wasobtained.

The aminoethylated percentage of this water-soluble polymer (120) wasmeasured with quantitative determination of unreacting carboxyl groupsby conductivity titration and the result indicated that the reactingmole number of ethyleneimine per one mole carboxyl group in this polymer(120) was 8.0.

Next, to this polymer were added 21.5 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the mixture was maintained at the boiling point for 3 hours tocomplete a reaction, whereby a hydrophilic resin (122) was obtained.

EXAMPLE 123

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 320.0 parts of water, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 95° C. under the nitrogen atmosphere. Next, to this was added amixture solution composed of 136.0 parts of sodium p-styrenesulfonate,24.0 parts of acrylic acid, and 160.0 parts of water, and furthermore,were added 106.7 parts of a 10% aqueous ammonium persulfate solutionduring 2 hours and, after the addition finished, 53.3 parts of a 10%aqueous ammonium persulfate solution were further added during 1 hour.After the addition finished, the reaction mixture was maintained at 95°C. for 1 hour to complete a polymerization reaction, whereby awater-soluble polymer having an average molecular weight of 17,000 (121)was obtained.

Next, to this polymer were added 128.0 parts of o-phthalic aciddiglycidyl ester ("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.)and the mixture was maintained at the boiling point for 3 hours tocomplete a reaction and completely neutralized with an aqueous sodiumhydroxide solution, whereby a hydrophilic resin (123) was obtained.

EXAMPLE 124

Into an autoclave a mixture composed of 98 parts of maleic anhydride,110 parts of a C₅ -olefinic mixture (in a composition of 15.34% ofiso-pentane, 15.28% of n-pentane, 41.97% of 2-methylbutene-1, 26.56% ofpentene-1, and 0.85% of isoprene), 4 parts of BPO, and 400 parts ofbenzene was subjected to reacting at 70° to 75° C. for 8 hours withheating and stirring. After the reaction finished, a reaction productseparated was collected with filtration and dried, whereby 96 parts of apolymer were obtained. A mixture of 84 parts of this polymer and 400parts of a 10% aqueous sodium hydroxide solution was warmed up to 80° to90° C. with stirring, whereby a water-soluble polymer having an averagemolecular weight of 4500 (122) was obtained. Next, to this polymer wereadded 10.1 parts of o-phthalic acid diglycidyl ester ("DENACOL EX-721",made by NAGASE CHEMICALS Co., Ltd.) and the mixture was maintained atthe boiling point for 3 hours to complete a reaction, whereby ahydrophilic resin (124) was obtained.

EXAMPLE 125

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 2326 parts of water, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 95° C. under the nitrogen atmosphere. Next, to this were added amixture solution composed of 386.8 parts of sodium 2-sulfoethylmethacrylate, 53.8 parts of acrylic acid, and 13.5 parts of water, amixture solution composed of 485.4 parts of sodium acrylate, and 826.6parts of water, and 251.4 parts of a 10% aqueous ammonium persulfatesolution during 2 hours. After the addition finished, 41.9 parts of 10%aqueous ammonium persulfate solution were further added during 20minutes. After the addition finished, the reaction mixture wasmaintained at 95° C. for 1 hour to complete a polymerization reaction,whereby a water-soluble polymer having an average molecular weight of4000 (123) was obtained.

Next, to 100 parts of this polymer (123) were added 100 parts of thewater-soluble polymer (1) obtained from the example 1 and 2.34 parts ofo-phthalic acid diglycidyl ester ("DENACOL EX-721", made by NAGASECHEMICALS Co., Ltd.) and the mixture was maintained at the boiling pointfor 3 hours to complete a reaction and completely neutralized with anaqueous sodium hydroxide solution, whereby a hydrophilic resin (125) wasobtained.

Example for comparison 9

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 16.0 parts of methyl acrylate, 16.0 parts of acrylic acid,0.64 parts of BPO, and 124.8 parts of IPA, and the inside atmosphere ofthe flask was replaced with stirring by nitrogen gas, the mixture in theflask was warmed up to the boiling point under the nitrogen atmosphereand maintained at this temperature for 30 minutes. Next, to this mixturewas added a mixture solution composed of 64.0 parts of methyl acrylate,64.0 parts of acrylic acid, 2.56 parts of BPO, and 499.2 parts of IPAduring 3 hours and, after the addition finished, were further added adispersed solution composed of 0.32 parts of BPO and 6.08 parts of IPAtwice with an hour interval. After the addition finished, the reactionmixture was maintained at the boiling point for 2 hours to complete apolymerization reaction, treated with distillation to remove IPA, andcompletely neutralized with an aqueous sodium hydroxide solution,whereby a copolymer for comparison (3) having an average molecularweight of 18,000 was obtained.

Example for comparison 10

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenser wasplaced a mixture composed of 5.30 parts of polyethyleneglycoldimethacrylate (an average mole number of added ethylene oxide is 9),32.0 parts of methacrylic acid, 1.0 part of BPO, and 127.0 parts of IPA,and the inside atmosphere of the flask was replaced with stirring bynitrogen gas, the mixture in the flask was warmed up to the boilingpoint under the nitrogen atmosphere. Next, to this mixture was added amixture composed of 6.17 parts of polyethyleneglycol dimethacrylate,38.0 parts of methacrylic acid, 1.1 parts of BPO, and 150.9 parts of IPAduring 2 hours and, after the addition finished, was further added 10.7parts of a 7% IPA solution of BPO during 1 hour. After the additionfinished, the reaction mixture was maintained at the boiling point for 1hour to complete a polymerization reaction, treated with distillation toremove IPA, and completely neutralized with an aqueous sodium hydroxidesolution, whereby an aqueous solution of a copolymer for comparison (4)was obtained.

The average molecular weights (weight average) of the above-obtainedwater-soluble polymers and the average molecular weights (weightaverage) after hydrolysis (in said way) of the above-obtained copolymerswere measured by GPC under said condition and results obtained are shownin the Table 5.

Also, viscosity of the hydrophilic resins and the copolymersabove-obtained was measured in said way and results obtained are shownin the Table 5.

EXAMPLE 126

Ordinary portland cement was used as cement (made by Sumitomo CementCo., Ltd.), river sand taken from Yodogawa as a fine aggregate (specificgravity of 2.51 and a fineness modulas [F. M.] 2.78), crashed stonesfrom Takatsuki (specific gravity of 2.68 and a fineness modulas [F. M.]of 6.73) as a coarse aggregate, and the hydrophilic resin (112) obtainedfrom the example 112 as a cement additive, and these materials wererespectively weighted to make 30 1 in amount of a kneaded mixture with acomposition of a unit ratio of 320 kg/m³ for cement, a unit ratio of 173kg/m³ for water (a ratio of water to cement was 54.2% ), a unit ratio of934 kg/m³ for fine aggregate, a unit ratio of 876 kg/m³ for coarseaggregate (a ratio of fine aggregate was 52%), and an addition amount0.12% (a ratio of the sol id portion against cement) of the hydrophilicresin (112), and all the materials were placed into a tilting mixer.Immediately, the mixing and kneading were carried out for 3 minutes witha rotation number of 35 r.p.m., and a fluid concrete having an objectslump of 18 cm and an object air amount of 4.5% was prepared (in a caseof that the object air amount is not attained, a slight amount of anair-entraining agent, [Vinsol] made by Yamaso Chemical Co., Ltd., wasused). An flowing concrete obtained immediately after the kneading wassampled and its slump and air amount were measured.

After the kneading finished, the rotation number of the tilting mixerwas reduced to 2 r.p.m., the mixing and kneading were further continued,and the slump and air amount were measured after 60 minutes, 90 minutes,and 120 minutes, to investigate their changes with time-passage.

Also, the compressive strength and setting time of the flowing concreteobtained were measured. Results obtained are shown in Table 5.

Besides, the measurement methods of the slump, air amount, compressivestrength, and setting time and the method to take a sample for testingthe compressive strength are based on the Japanese Industrial standards(JIS A6204).

EXAMPLES 127 TO 139

The procedure of example 126 was repeated except that the hydrophilicresins (113) to (125) obtained from the examples 113 to 125 as shown inTable 5 were used as cement additives in the amounts for adding shown inTable 5, and flowing concretes thus-prepared were measured in the slump,air amount, compressive strength, and setting time. Results obtained areshown in Table 5.

Example for comparison 11

The procedure of example 126 was repeated except that the copolymer forcomparison (3) was used as a cement additive in an amount for adding of0.40% (against cement) instead of the hydrophilic resin (112), and aflowing concrete for comparison thus-prepared was measured in the slump,air amount, compressive strength, and setting time. Results obtained areshown in Table 5.

Example for comparison 12

The procedure of example 126 was repeated except that the copolymer forcomparison (4) was used as a cement additive in an amount for adding of0.35% (against cement) instead of the hydrophilic resin (112), and aflowing concrete for comparison thus-prepared was measured in the slump,air amount, compressive strength, and setting time. Results obtained areshown in Table 5.

                                      TABLE 5                                     __________________________________________________________________________                                           The upper side: Slump (cm)                     Water-soluble                                                                          Cement admixture used The middle side: Air amount (%)                polymer              Addition amount                                                                         The under side: Residual % of                                                 slump(*3)                                         Molecular    Viscosity                                                                          (solid portion, %)                                                                      Immediately                                                                           after 60                                                                           after                                                                              after 120                    No.                                                                              weight(*1)   (cps)(*2)                                                                          (against cement)                                                                        after kneading                                                                        minutes                                                                            minutes                                                                            minutes              __________________________________________________________________________    Example 126                                                                           (112)                                                                             4,000                                                                              Hydrophilic                                                                          8,000                                                                              0.30      12.3    17.4 18.5 17.0                                  resin                 4.0     4.9  5.1  5.0                                   (112)                 --      141  150  138                  Example 127                                                                           (112)                                                                             4,000                                                                              Hydrophilic                                                                          9,000                                                                              0.40      18.0    16.9 14.8 10.9                                  resin                 4.0     3.9  3.8  3.7                                   (113)                 --      94   82   61                   Example 128                                                                           (113)                                                                            28,000                                                                              Hydrophilic                                                                          49.1 0.30      17.8    17.7 17.4 17.0                                  resin                 4.5     4.2  4.3  4.0                                   (114)                 --      99   98   96                   Example 129                                                                           (114)                                                                             3,000                                                                              Hydrophilic                                                                          30.4 0.20      18.3    19.0 18.0 17.4                                  resin                 4.9     4.9  4.9  4.3                                   (115)                 --      104  98   95                   Example 130                                                                           (115)                                                                             5,200                                                                              Hydrophilic                                                                          46.7 0.20      17.8    18.4 17.9 17.1                                  resin                 4.5     4.6  4.7  4.3                                   (116)                 --      103  101  96                   Example 131                                                                           (116)                                                                            18,000                                                                              Hydrophilic                                                                          73.4 0.22      17.8    18.4 18.0 17.4                                  resin                 4.1     4.5  4.6  4.3                                   (117)                 --      103  101  98                   Example 132                                                                           (116)                                                                            18,000                                                                              Hydrophilic                                                                          84.3 0.35      17.3    17.0 14.8 12.1                                  resin                 4.3     4.3  4.2  4.0                                   (118)                 --      98   86   70                   Example 133                                                                           (117)                                                                             6,400                                                                              Hydrophilic                                                                          38.1 0.30      18.3    18.7 18.4 17.8                                  resin                 4.0     4.2  4.5  4.4                                   (119)                 --      102  101  97                   Example 134                                                                           (118)                                                                             7,800                                                                              Hydrophilic                                                                          55.8 0.30      17.2    18.8 18.4 17.3                                  resin                 3.8     4.0  4.7  4.4                                   (120)                 --      109  107  101                  Example 135                                                                           (119)                                                                            25,000                                                                              Hydrophilic                                                                          80.4 0.30      18.8    18.5 18.0 17.0                                  resin                 4.5     4.8  4.5  4.3                                   (121)                 --      98   96   90                   Example 136                                                                           (120)                                                                            40,000                                                                              Hydrophilic                                                                          104.5                                                                              0.30      18.3    18.0 17.3 17.1                                  resin                 4.7     4.3  4.2  4.0                                   (122)                 --      98   95   93                   Example 137                                                                           (121)                                                                            17,000                                                                              Hydrophilic                                                                          43.1 0.26      18.4    18.0 17.4 16.8                                  resin                 3.7     3.9  4.0  3.7                                   (123)                 --      98   95   91                   Example 138                                                                           (122)                                                                             4,500                                                                              Hydrophilic                                                                          31.3 0.23      17.8    17.6 17.0 16.6                                  resin                 4.0     4.5  4.3  4.0                                   (124)                 --      99   96   93                   Example 139                                                                           (123)                                                                             4,000                                                                              Hydrophilic                                                                          52.0 0.20      16.2    19.8 19.2 19.0                          (1)                                                                             20,000                                                                              resin                 4.3     4.5  4.4  4.3                                   (125)                 --      122  119  117                  Example for                                                                           -- 18,000                                                                              Copolymer                                                                            18.4 0.40      17.9    8.1  --   --                   comparison 11    for compari-          3.8     4.0  --   --                                    son (3)               --      45   --   --                   Example for                                                                           -- 20,000                                                                              Copolymer                                                                            41.3 0.35      18.2    7.5  --   --                   comparison 12    for compari-          4.2     4.0  --   --                                    son (4)               --      41   --   --                   __________________________________________________________________________                                                    Condensation                                                                          Setting time                                                          strength                                                                              (hour:minute)                                                         age of 28                                                                             (beginning/                                                           days (kg/cm.sup.2)                                                                    finishing)            __________________________________________________________________________                                            Example 126                                                                           318     5:48/7:41                                                     Example 127                                                                           303     5:58/7:48                                                     Example 128                                                                           340     5:13/7:25                                                     Example 129                                                                           339     5:40/7:50                                                     Example 130                                                                           325     5:27/7:41                                                     Example 131                                                                           318     5:38/7:44                                                     Example 132                                                                           329     5:17/7:24                                                     Example 133                                                                           331     5:24/7:19                                                     Example 134                                                                           320     5:31/7:28                                                     Example 135                                                                           311     5:19/7:30                                                     Example 136                                                                           340     5:13/7:28                                                     Example 137                                                                           333     5:04/7:11                                                     Example 138                                                                           314     5:20/7:14                                                     Example 139                                                                           353     5:18/7:24                                                     Example for                                                                           338     5:45/7:51                                                     comparison 11                                                                 Example for                                                                           302     6:25/8:31                                                     comparison 12                         __________________________________________________________________________     (*1)Measured by G.P.C.                                                        (*2)Measured by a B type rotational viscometer at 20° C. and 20%       ##STR25##                                                                

EXAMPLE 140

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 58.1 parts of water, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto 50° C. under the nitrogen atmosphere. Next, to this were added amonomer mixture solution composed of 5.21 parts of2-acrylamido-2-methylpropanesulfonic acid, 0.42 parts of sodiummethacrylate, 20.5 parts of methacrylic acid, 93.9 parts ofmethoxypolyethyleneglycol monomethacrylate (an average mole number ofadded ethylene oxide is 9), and 187.7 parts of water and, in addition,18.2 parts of a 20% aqueous ammonium persulfate solution and 9.12 partsof a 20% sodium hydrogen sulfite solution during 4 hours and, after theaddition finished, 4.6 parts of a 20% aqueous ammonium persulfatesolution and 2.3 parts of a 20% sodium hydrogen sulfite solution werefurther added during 1 hour. After the addition finished, the reactionmixture was maintained at 50° C. for 1 hour to complete a polymerizationreaction, whereby an aqueous solution of a water-soluble polymer havingan average molecular weight of 12,000 (140) was obtained.

Next, to this polymer were added 200.0 parts of water and 4.0 parts ofo-phthalic acid diglycidyl ester ("DENACOL EX-721", made by NAGASECHEMICALS Co., Ltd.) and the mixture was maintained at the boiling pointfor 3 hours to complete a reaction and completely neutralized with anaqueous sodium hydroxide solution, whereby a hydrophilic resin (140) wasobtained.

EXAMPLE 141

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a nitrogen gas-inlet tube, and a refluxcondenser were placed 58.1 parts of water, and the inside atmosphere ofthe flask was replaced with stirring by nitrogen gas and the flask waswarmed up to 50° C. under the nitrogen atmosphere. Next, to this wereadded a monomer mixture solution composed of 5.21 parts of sodium2-sulfoethylmethacrylate, 0.42 parts of sodium methacrylate, 20.5 partsof methacrylic acid, 93.9 parts of methoxypolyethylene glycolmonomethacrylate (an average mole number of added ethylene oxide is 9),and 187.7 parts of water and, in addition, 18.2 parts of a 20% aqueousammonium persulfate solution and 9.12 parts of a 20% sodium hydrogensulfite solution during 4 hours, respectively and, after the additionfinished, 4.6 parts of a 20% aqueous ammonium persulfate solution and2.3 parts of a 20% sodium hydrogen sulfite solution were further addedduring 1 hour. After the addition finished, the reaction mixture wasmaintained at 50° C. for 1 hour to complete a polymerization reaction,whereby a 20% aqueous solution of a water-soluble polymer having anaverage molecular weight of 10,000 (141) was obtained. Next, to thispolymer were added 3.2 parts of o-phthalic acid diglycidyl ester("DENACOL EX-721", made by NAGASE CHEMICALS Co., Ltd.) and the mixturewas maintained at the boiling point for 3 hours to complete a reactionand completely neutralized with an aqueous sodium hydroxide solution,whereby a hydrophilic resin (141) was obtained.

EXAMPLE 142

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 707.5 parts of water, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wereadded 180.0 parts of a 80% aqueous acrylic acid solution, 16.0 parts ofvinylsulfonic acid and 195.6 parts of an 5% aqueous sodium persulfatesolution during 4 hours. After the addition finished, the reactionmixture was maintained at the boiling point for 1 hour to complete apolymerization reaction and then, partially neutralized with an aqueoussodium hydroxide solution, whereby a water-soluble polymer having anaverage molecular weight of 5000 (142) was obtained. Next, to 500.0parts of the aqueous solution of the water-soluble polymer (142) whoseconcentration was adjusted at 40% by distilling water were added 10.0parts of the compound used in the example 16 ("DENACOL EX-202", made byNAGASE CHEMICALS Co., Ltd.) and the mixture was maintained at theboiling point for 3 hours to complete a reaction and completelyneutralized with an aqueous sodium hydroxide solution, whereby ahydrophilic resin (142) was obtained.

EXAMPLE 143

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 707.5 parts of water, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wereadded 180.0 parts of a 80% aqueous acrylic acid solution, 16.0 parts ofdiethylaminoethylmethacrylamide, and 195.6 parts of an 5% aqueous sodiumpersulfate solution during 4 hours. After the addition finished, thereaction mixture was maintained at the boiling point for 1 hour tocomplete a polymerization reaction and then, partially neutralized withan aqueous sodium hydroxide solution, whereby a water-soluble polymerhaving an average molecular weight of 6000 (143) was obtained. Next, to500.0 parts of the aqueous solution of the water-soluble polymer (143)whose concentration was adjusted at 40% by distilling water were added10.0 parts of the compound used in the example 16 ("DENACOL EX-202",made by NAGASE CHEMICALS Co., Ltd.) and the mixture was maintained atthe boiling point for 3 hours to complete a reaction and completelyneutralized with an aqueous sodium hydroxide solution, whereby ahydrophilic resin (143) was obtained.

EXAMPLE 144

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 760.9 parts of IPA, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wereadded a mixture solution composed of 48.0 parts of a compound having theforementioned structure ("Kayarad R-526", made by Nippon Kayaku Co.,Ltd.), 40.1 parts of 2-acrylamido-2-methylpropanesulfonic acid, 237.9parts of methoxypolyethylene glycol monomethacrylate ("NK-ester M-9G",made by SHIN-NAKAMURA CHEMICAL Co., Ltd.; an average mole number ofadded ethylene oxide is 9), 108.2 parts of methacrylic acid, 15.1 partsof sodium methacrylate, and 624.2 parts of water and, in addition, 151.7parts of a 2.5% aqueous ammonium persulfate solution during 4 hours and,after the addition finished, 37.9 parts of a 2.5% aqueous ammoniumpersulfate solution were added during 1 hour. After the additionfinished, the reaction mixture was maintained at the boiling point for 1hour to complete a polymerization reaction, then treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(144) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (144) is as shown in the table 6.

EXAMPLE 145

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 760.9 parts of IPA, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wereadded a mixture solution composed of 48.0 parts of a compound having thefollowing structure ("DA-721", made by NAGASE CHEMICALS Co., Ltd.), 40.1parts of 2-sulfoethylmethacrylate, 237.9 parts of methoxypolyethyleneglycol monomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICALCo., Ltd.; an average mote number of added ethylene oxide is 9), 108.2parts of methacrylic acid, 15.1 parts of sodium methacrylate, and 624.2parts of water and, in addition, 151.7 parts of a 2.5% aqueous ammoniumpersulfate solution during 4 hours and, after the addition finished,37.9 parts of a 2.5% aqueous ammonium persulfate solution were addedduring hour. After the addition finished, the reaction mixture wasmaintained at the boiling point for 1 hour to complete a polymerizationreaction, then treated with distillation to remove IPA, and completelyneutralized with an aqueous sodium hydroxide solution, whereby anaqueous solution of a copolymer (145) was obtained. The viscosity of a20% aqueous solution of this copolymer (145) is as shown in the Table 6.##STR26##

EXAMPLE 146

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 760.9 parts of IPA, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wereadded a mixture solution composed of 48.0 parts of a compound having theforementioned structure ("Kayarad R-526", made by Nippon Kayaku Co.,Ltd.), 40.1 parts of N,N-dimethylaminoethyl methacrylate, 237.9 parts ofmethoxypolyethylene glycol monomethacrylate ("NK-ester M-9G", made bySHIN-NAKAMURA CHEMICAL Co., Ltd.; an average mole number of addedethylene oxide is 9), 108.2 parts of methacrylic acid, 15.1 parts ofsodium methacrylate, and 624.2 parts of water and, in addition, 151.7parts of a 2.5% aqueous ammonium persulfate solution during 4 hours and,after the addition finished, 37.9 parts of a 2.5% aqueous ammoniumpersulfate solution were added during 1 hour. After the additionfinished, the reaction mixture was maintained at the boiling point for 1hour to complete a polymerization reaction, then treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(146) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (146) is as shown in the table 6.

EXAMPLE 147

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 760.9 parts of IPA, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wereadded a mixture solution composed of 48.0 parts of a compound having theforementioned structure ("Kayarad R- 526", made by Nippon Kayaku Co.,Ltd.), 60.2 parts of styrenesulfonic acid, 217.8 parts ofmethoxypolyethylene glycol monomethacrylate ("NK-ester M-9G", made bySHIN-NAKAMURA CHEMICAL Co., Ltd.; an average mole number of addedethylene oxide is 9), 108.2 parts of methacrylic acid, 15.1 parts ofsodium methacrylate, and 624.2 parts of water and, in addition, 151.7parts of a 2.5% aqueous ammonium persulfate solution during 4 hours and,after the addition finished, 37.9 parts of a 2.5% aqueous ammoniumpersulfate solution were added during 1 hour. After the additionfinished, the reaction mixture was maintained at the boiling point for 1hour to complete a polymerization reaction, then treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(147) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (147) is as shown in the Table 6.

EXAMPLE148

Into glass-made reaction vessel equipped with a thermometer, a stirrer,a dropping funnel, a gas-inlet tube, and a reflux condenser were placed760.9 parts of IPA, and the inside atmosphere of the flask was replacedwith stirring by nitrogen gas and the flask was warmed up to the boilingpoint under the nitrogen atmosphere. Next, to this were added a mixturesolution composed of 48.0 parts of a compound having the forementionedstructure ("Kayarad R-526", made by Nippon Kayaku Co., Ltd.), 60.2 partsof vinylsulfonic acid, 217.8 parts of methoxypolyethylene glycolmonomethacrylate ("NK-ester M-9G", made by SHIN-NAKAMURA CHEMICAL CO.,Ltd.; an average mole number of added ethylene oxide is 9), 108.2 partsof methacrylic acid, 15.1 parts of sodium methacrylate, and 624.2 partsof water and, in addition, 151.7 parts of a 2.5% aqueous ammoniumpersulfate solution during 4 hours and, after the addition finished,37.9 parts of a 2.5% aqueous ammonium persulfate solution were addedduring 1 hour. After the addition finished, the reaction mixture wasmaintained at the boiling point for 1 hour to complete a polymerizationreaction, then treated with distillation to remove IPA, and completelyneutralized with an aqueous sodium hydroxide solution, whereby anaqueous solution of a copolymer (148) was obtained. The viscosity of a20% aqueous solution of this copolymer (148) is as shown in the Table 6.

EXAMPLE 149

Into a glass-made reaction vessel equipped with a thermometer, astirrer, a dropping funnel, a gas-inlet tube, and a reflux condenserwere placed 760.9 parts of IPA, and the inside atmosphere of the flaskwas replaced with stirring by nitrogen gas and the flask was warmed upto the boiling point under the nitrogen atmosphere. Next, to this wereadded a mixture solution composed of 50.0 parts of a compound having thefollowing structure ("DM-832", made by NAGASE CHEMICALS Co., Ltd.), 80.3parts of diethylaminoethylmethacrylamide, 197.7 parts ofmethoxypolyethylene glycol monomethacrylate ("NK-ester M-9G", made bySHIN-NAKAMURA CHEMICAL Co., Ltd.; an average mole number of addedethylene oxide is 9), 108.2 parts of methacrylic acid, 15.1 parts ofsodium methacrylate, and 624.2 parts of water and, in addition, 151.7parts of a 2.5% aqueous ammonium persulfate solution during 4 hours and,after the addition finished, 37.9 parts of a 2.5% aqueous ammoniumpersulfate solution were added during 1 hour. After the additionfinished, the reaction mixture was maintained at the boiling point for 1hour to complete a polymerization reaction, then treated withdistillation to remove IPA, and completely neutralized with an aqueoussodium hydroxide solution, whereby an aqueous solution of a copolymer(149) was obtained. The viscosity of a 20% aqueous solution of thiscopolymer (149 ) is as shown in the Table 6. ##STR27##

The average molecular weights (weight average) of the above-obtainedwater-soluble polymers and the average molecular weights (weightaverage) after hydrolysis (in said way) of the above-obtained copolymerswere measured by GPC under said condition and results obtained are shownin the Table 6.

Also, viscosity of the hydrophilic resins and the copolymersabove-obtained was measured in said way and results obtained are shownin the Table 6.

EXAMPLE 150

Ordinary portland cement was used as cement (made by Sumitomo CementCo., Ltd.), river sand taken from Yodogawa as a fine aggregate (specificgravity of 2.51 and a fineness modulas [F. M.] of 2.78), crashed stonesfrom Takatsuki (specific gravity of 2.68 and a fineness modulas [F. M.]of 6.73) as a coarse aggregate, and the hydrophilic resin (140) obtainedfrom the example 140 as a cement additive, and these materials wererespectively weighted to make 30 1 in amount of a kneaded mixture with acomposition of a unit ratio of 320 kg/m³ for cement, a unit ratio of 173kg/m³ for water (a ratio of water to cement was 54.2% ), a unit ratio of934 kg/m ³ for fine aggregate, a unit ratio of 876 kg/m³ for coarseaggregate (a ratio of fine aggregate was 52% ), and an addition amount0.15% (a ratio of the solid portion against cement) of the hydrophilicresin (140 ) , and all the materials were placed into a tilting mixer.Immediately, the mixing and kneading were carried out for 3 minutes witha rotation number of 35 r.p.m., and a flowing concrete having an objectslump of 18 cm and an object air amount of 4.5% was prepared (in a caseof that the object air amount is not attained, a slight amount of anair-entraining agent, [Vinsol] made by Yamaso Chemical Co., Ltd., wasused). An flowing concrete obtained immediately after the kneading wassampled and its slump and air amount were measured.

After the kneading finished, the rotation number of the tilting mixerwas reduced to 3 r.p.m., the mixing and kneading were further continued,and the slump and air amount were measured after 60 minutes, 90 minutes,and 120 minutes, to investigate their changes with time-passage.

Also, the compressive strength and setting time of the flowing concreteobtained were measured. Results obtained are shown in Table 6.

Besides, the measurement methods of the slump, air amount, compressivestrength, and setting time and the method to take a sample for testingthe compressive strength are based on the Japanese Industrial standards(JIS A6204).

EXAMPLES 151 TO 153

The procedure of example 150 was repeated except that the hydrophilicresins (141) to (143) obtained from the examples 141 to 143 as shown inTable 6 were used as cement additives in the amounts for adding shown inTable 6, and flowing concretes thus-prepared were measured in the slump,air amount, compressive strength, and setting time. Results obtained areshown in Table 6.

EXAMPLES 154 TO 159

The procedure of example 150 was repeated except that the copolymers(144) to (149) obtained from the examples 144 to 149 as shown in Table 6were used as cement additives in the amounts for adding shown in Table6, and flowing concretes thus-prepared were measured in the slump, airamount, compressive strength, and setting time. Results obtained areshown in Table 6.

                                      TABLE 6                                     __________________________________________________________________________                                           The upper side: Slump (cm)                     Water-soluble                                                                          Cement admixture used The middle side: Air amount (%)                polymer              Addition amount                                                                         The under side: Residual % of                                                 slump(*3)                                         Molecular    Viscosity                                                                          (solid portion, %)                                                                      Immediately                                                                           after 60                                                                           after                                                                              after 120                    No.                                                                              weight(*1)   (cps)(*2)                                                                          (against cement)                                                                        after kneading                                                                        minutes                                                                            minutes                                                                            minutes              __________________________________________________________________________    Example 150                                                                           (140)                                                                            12,000                                                                              Hydrophilic                                                                          2,100                                                                              0.15      18.9    18.9 18.0 17.5                                  resin                 5.1     5.1  5.0  4.9                                   (140)                 --      100  95   93                   Example 151                                                                           (141)                                                                            10,000                                                                              Hydrophilic                                                                          900  0.15      18.4    18.0 17.4 17.0                                  resin                 4.8     4.9  4.7  4.6                                   (141)                 --      98   95   92                   Example 152                                                                           (142)                                                                             5,000                                                                              Hydrophilic                                                                          1,200                                                                              0.22      18.6    18.8 18.3 17.5                                  resin                 4.3     4.5  4.8  4.5                                   (142)                 --      101  98   94                   Example 153                                                                           (143)                                                                             6,000                                                                              Hydrophilic                                                                          1,800                                                                              0.26      18.0    18.3 18.4 17.8                                  resin                 4.0     4.3  4.7  4.5                                   (143)                 --      102  102  99                   Example 154                                                                           -- 15,000(*4)                                                                          Copolymer                                                                            90.4 0.12      18.3    18.5 18.4 17.8                                  (144)                 4.5     4.7  4.9  4.6                                                         --      101  101  97                   Example 155                                                                           -- 12,000(*4)                                                                          Copolymer                                                                            68.3 0.12      17.8    18.5 18.2 17.1                                  (145)                 4.3     4.6  4.5  4.1                                                         --      104  102  96                   Example 156                                                                           -- 13,000(*4)                                                                          Copolymer                                                                            75.4 0.14      18.3    18.5 18.0 17.3                                  (146)                 4.0     4.5  4.7  4.1                                                         --      101  98   95                   Example 157                                                                           -- 13,000(*4)                                                                          Copolymer                                                                            80.1 0.12      18.1    18.3 18.5 18.0                                  (147)                 4.3     4.6  4.6  4.2                                                         --      101  102  99                   Example 158                                                                           -- 10,000(*4)                                                                          Copolymer                                                                            61.8 0.12      17.8    18.0 18.2 17.5                                  (148)                 4.0     4.4  4.6  4.2                                                         --      101  102  98                   Example 159                                                                           -- 12,000(*4)                                                                          Copolymer                                                                            78.5 0.12      18.5    17.8 16.5 12.4                                  (149)                 4.8     4.7  4.5  4.1                                                         --      96   89   67                   __________________________________________________________________________                                                    Condensation                                                                          Setting time                                                          strength                                                                              (hour:minute)                                                         age of 28                                                                             (beginning/                                                           days (kg/cm.sup.2)                                                                    finishing)            __________________________________________________________________________                                            Example 150                                                                           338     5:10/7:40                                                     Example 151                                                                           350     5:12/7:29                                                     Example 152                                                                           343     5:40/7:51                                                     Example 153                                                                           330     5:38/7:43                                                     Example 154                                                                           337     5:30/7:40                                                     Example 155                                                                           351     5:21/7:15                                                     Example 156                                                                           320     5:13/7:27                                                     Example 157                                                                           341     5:18/7:21                                                     Example 158                                                                           323     5:29/7:41                                                     Example 159                                                                           337     5:10/7:15             __________________________________________________________________________     (*1)Measured by G.P.C.                                                        (*2)Measured by a B type rotational viscometer at 20° C. and 20%       ##STR28##                                                                     (*4)Molecular weight after hydrolysis of copolymer                       

From the result as shown in the Tables 1 to 6, it is apparent thatcement additives of the present invention show almost no retardation ofsetting and manifest a superior property to prevent a slump loss.

We claim:
 1. A cement additive comprising a crosslinked polymer inwhich, between main chains having a water-soluble polymer structure of aweight average molecular weight from 500 to 100,000, a bond having as astructural unit at least one divalent group having the following formula(I) is formed ##STR29## wherein R¹ and R² independently are selectedfrom the group consisting of: ##STR30## with the proviso that R¹ is notrequired if R² is ##STR31## and wherein R and R' independently denote analkyl group of carbon number of 1 to 5, said crosslinked polymer havinga maximum viscosity of 100,000 cps in a 20% by weight aqueous solutionor dispersion at a temperature of 20° C.,wherein said main chainscomprise at least one member selected from the group consisting of##STR32## wherein m is 0 or an integral number of 1 to 50; n is 0 or 1;M is at least one member selected from the group consisting of ahydrogen atom, a monovalent, divalent or trivalent metal group, anammonium group and an organic amine group; R⁵ and R⁶ independentlydenote an alkylene group of carbon number 2 to 4; R⁷ denotes an alkylenegroup of carbon number 1 to 5; with the proviso that when m is at least2, a plurality of R⁵ O may be the same or different and, when aplurality of R⁵ O are different from one another, their arrangement maybe regular or irregular; and wherein said main chains further compriseat least one functional group selected from the group consisting of##STR33## wherein p is an integral number of 1 to 10; q is 0 or anintegral number of 1 to 100; r and s are, respectively, an integralnumber of 1 to 3; t and u are, respectively, an integral number of 1 to100; A¹ is a straight chain divalent or branched trivalent ring-openedgroup of an alkyleneimine of 2 to 4 carbon atoms; R⁸ denotes CH₃ or C₂H₅ ; R⁹ denotes H, CH₃, or C₂ H₅ ; R¹⁰ denotes H or an alkyl group ofcarbon number 1 to 5; and X.sup.⊖ denotes an anionic pair ion, with theproviso that, when p is at least two, a plurality of A¹ groups may bethe same or different and, when a plurality of A¹ are different from oneanother, their arrangement may be regular or irregular; and with theprovision that when q is an integral number of from 1-100, thearrangement of A¹ and R⁵ O may be normal or reverse and may be regularor irregular, and wherein q is at least 2, when t is at least 2, andwhen u is at least 2, respectively, a plurality of R⁵ O may be the sameor different and, when a plurality of R⁵ O are different from oneanother, their arrangement may be regular or irregular, and wherein saidcrosslinked polymer is capable of forming a water-soluble polymer bycleavage of the divalent group in an alkaline medium.
 2. A method forproducing a cement additive which comprises obtaining a crosslinkedpolymer by combining water-soluble polymers having a weight averagemolecular weight of 500 to 100,000 to one another by using acrosslinking agent which has a structural unit or is capable of formingat least one divalent group having the following formula (I): ##STR34##wherein R¹ and R² independently are selected from the group consistingof: ##STR35## with the proviso that R¹ is not required if R² is##STR36## and wherein R and R' independently denote an alkyl group ofcarbon number of 1 to 5,said crosslinked polymer having a maximumviscosity of 100,000 cps in a 20% by weight aqueous solution ordispersion at a temperature of 20° C., wherein the water-soluble polymercomprises at least one member selected from the group consisting of##STR37## wherein m is 0 or an integral number of 1 to 50; n is 0 or 1;M is at least one member of the group consisting of a hydrogen atom, amonovalent, divalent or trivalent metal group, an ammonium group, and anorganic amine group, R⁵ and R⁶ independently denote an alkylene group ofcarbon number 2 to 4; R⁷ denotes an alkylene group of carbon number 1 to5, with the proviso that when m is at least 2, a plurality of R⁵ O maybe the same or different and, when a plurality of R⁵ O are differentfrom one another, their arrangement may be regular or irregular, andwherein the water-soluble polymer further comprises at least onefunctional group selected from the group consisting of ##STR38## whereinp is an integral number of 1 to 10, q is 0 or an integral number of 1 to100; r and s are, respectively, an integral number of 1 to 3; t and uare, respectively, an integral number of 1 to 100; A¹ is a straightchain divalent or branched trivalent ring-opened group of analkyleneimine of 2 to 4 carbon atoms; R⁸ denotes CH₃ or C₂ H₅ ; R⁹denotes H, CH₃, or C₂ H₅ ; R¹⁰ denotes H or an alkyl group of carbonnumber 1 to 5; and X.sup.⊖ denotes an anionic pair ion, with the provisothat, when p is at least two, a plurality of A¹ may be the same ordifferent and, when a plurality of A¹ are different from one another,their arrangement may be regular or irregular, with the proviso thatwhen q is an integral number of from 1 to 100, the arrangement of A¹ andR⁵ O may be normal or reverse and may be regular or irregular, with theproviso that when q is at least 2, when t is at least 2, and when u isat least 2, respectively, a plurality of R⁵ O may be the same ordifferent and when a plurality of R⁵ O are different from one another,their arrangement may be regular or irregular, and wherein saidcrosslinked polymer is capable of forming a water-soluble polymer bycleavage of the divalent group in an alkaline medium.
 3. A method forproducing a cement additive which comprises obtaining a crosslinkedpolymer by combining water-soluble polymers having a weight averagemolecular weight of 500 to 100,000 to one another by using acrosslinking agent which has a structural unit or is capable of formingat least one divalent group having the following formula (I): ##STR39##wherein R¹ and R² independently are selected from the group consistingof: ##STR40## with the proviso that R¹ is not required if R² is##STR41## and wherein R and R' independently denote an alkyl group ofcarbon number of 1 to 5,said crosslinked polymer having a maximumviscosity of 100,000 cps in a 20% by weight aqueous solution ordispersion at a temperature of 20° C., wherein the water-soluble polymercomprises --COOM and--COO--(R⁵ O)_(u) --R¹⁰ wherein M is at least onemember of the group consisting of a hydrogen atom, a monovalent,divalent or trivalent metal group, an ammonium group, and an organicamine group, R⁵ denotes an alkylene group of carbon number 2 to 4; u isan integral number of 1 to 100; and R¹⁰ denotes H or an alkyl group ofcarbon number 1 to 5, with the proviso that when u is at least 2, aplurality of R⁵ O may be the same or different and when a plurality ofR⁵ O are different from one another, their arrangement may be regular orirregular, wherein the water-soluble polymer is derived from a(poly)alkyleneglycol mono(meth)acrylate monomer (xiv) in an amount of 1to 99.9% by weight and a (meth)acrylic monomer (i) in an amount of 99 to0.1% by weight wherein the total (xiv) and (i) is 100% by weight and thecrosslinking agent has a functional group capable of reacting with atleast one functional group selected from the group consisting of acarboxyl group and a hydroxyl group being contained in the water-solublepolymer, and the crosslinking agent and the water-soluble polymer areused in a molar ratio range of 0.001 to 1.0 between a functional groupof said crosslinking agent and a functional group of said water-solublepolymer wherein said monomer (i) has the structure: ##STR42## wherein Mis at least one member selected from the group consisting of a hydrogenatom, a monovalent, divalent or trivalent metal group, an ammonium groupand an organic amine group; and R³ denotes H or CH₃ ; wherein saidmonomer (xiv) has the formula: ##STR43## wherein u is the integralnumber of 1 to 100; with the proviso that, when u is at least 2, aplurality of R⁵ O may be the same or different and, when a plurality ofR⁵ O are different from one another, their arrangement may be regular orirregular; and wherein said crosslinked polymer is capable of forming awater-soluble polymer by cleavage of the divalent group in an alkalinemedium.
 4. A method for producing a cement additive which comprisesobtaining a crosslinked polymer by a polymerization reaction of amonomer (e), which has at least two polymerizable double bonds and hasas a structural unit at least one divalent group having thebelow-described formula (I) between the double bonds, with a monomer(f), which has one polymerizable double bond capable of copolymerizingwith the double bond in (e) and is able to form a main chain structurecapable of leading to a water-soluble polymer of a weight averagemolecular weight of 500 to 100,000 ##STR44## wherein R¹ and R²independently are selected from the group consisting of: ##STR45## withthe proviso that R¹ is not required if R² is ##STR46## and wherein R andR' independently denote an alkyl group of carbon number of 1 to 5, saidcrosslinked polymer having a maximum viscosity of 100,000 cps in a 20%by weight aqueous solution or dispersion at a temperature of 20°C.,wherein the water-soluble polymer comprises at least one groupselected from the group consisting of ##STR47## wherein m is 0 or anintegral number of 1 to 50; n is0 or 1; M is at least one memberselected from the group consisting of a hydrogen atom, a monovalent,divalent or trivalent metal group, an ammonium group and an organicamine group; R⁵ and R⁶ independently denote an alkylene group of 2 to 4carbon atoms; R⁷ denotes an alkylene group of 1 to 5 carbon atoms; withthe proviso that when m is at least 2, a plurality of R⁵ O may be thesame or different, and when a plurality of R⁵ O are different from oneanother, their arrangement may be regular or irregular, and wherein thewater-soluble polymer further comprises at least one group selected fromthe group consisting of ##STR48## wherein p is an integral number of 1to 10; q is 0 or an integral number of 1 to 100; r and s are,respectively, an integral number of 1 to 3; t and u are, respectively,an integral number of 1 to 100; A¹ is a straight chain divalent orbranched trivalent ring-opened group of an alkyleneimine of 2 to 4carbon atoms; R⁸ denotes CH₃ or C₂ H₅ ; R⁹ denotes H, CH₃ or C₂ H₅ ; R¹⁰denotes H or an alkyl group of carbon number 1 to 5; and X.sup.⊖ denotesan anionic pair ion, with the proviso that when p is at least two, aplurality of A¹ may be the same or different and, when a plurality of A¹are different from one another, their arrangement may be regular orirregular; and with the proviso that when q is an integral number offrom 1-100, the arrangement of A¹ and R⁵ O may be normal or reverse andmay be regular or irregular; and with the proviso that when q is atleast 2, when t is at least 2, and when u is at least 2 respectively, aplurality of R⁵ O may be the same or different and, when a plurality ofR⁵ O are different from one another, their arrangement may be regular orirregular; and wherein said crosslinked polymer is capable of forming awater-soluble polymer by cleavage of the divalent group in an alkalinemedium.
 5. A method for producing a cement additive as claimed in claim3, wherein the crosslinking agent is a polyvalent glycidyl compound. 6.A method for producing a cement additive as claimed in claim 2, in whichthe crosslinking agent has a weight average molecular weight of 100 to5,000.
 7. A method for producing a cement additive as claimed in claim4, which comprises obtaining a crosslinked polymer by reacting a monomer(e) in an amount of 0.1 to 50% by weight, with a monomer (xiv) in aseries of (poly)alkyleneglycol mono(meth)acrylates present in an amountof 1 to 98.9% by weight, and a monomer (i) in a series of (meth)acrylicmonomers present in an amount of 1 to 98.9% by weight such that thetotal amount of (e), (xiv) and (i) is 100% by weight wherein saidmonomer (i) has the structure: ##STR49## wherein M is at least onemember selected from the group consisting of a hydrogen atom, amonovalent, divalent or trivalent metal group, an ammonium group and anorganic amine group; R³ denotes H or CH₃ and wherein said monomer (xiv)has the structure: ##STR50## wherein u is an integral number of 1 to100; R³ is defined above; R⁵ denotes an alkylene group of carbon number2 to 4; R¹⁰ denotes H or an alkyl group of carbon number 1 to 5, suchthat when u is at least 2, a plurality of R⁵ O may be the same ordifferent and, when a plurality of R⁵ O are different from one another,their arrangement may be regular or irregular.
 8. A method for producinga cement additive as claimed in claim 4, in which a monomer (e) is atleast one member selected from the group consisting ofA product from areaction of at least one compound selected from monoester diols andpolyester polyols with a polymerizable monomer having a functional groupcapable of reacting with a hydroxy group in said diols and polyols, Aproduct from a reaction of at least one compound selected from monoesterdicarboxylic acids and polyester polycarboxylic acids with apolymerizable monomer having a functional group capable of reacting witha carboxyl group in said acids, A product from a reaction of at leastone compound selected from polyols and polyepoxy compounds with apolymerizable monomer having a carboxyl group separated from apolymerizable double bond by at least one carbon atom, A product from areaction of at least one compound selected from polycarboxylic acidswith a polymerizable monomer having a hydroxyl group or an epoxy groupseparated from a polymerizable double bond by at least one carbon atom,and, A product from a reaction of at least one compound selected frommonoester polyepoxy compounds and polyester polyepoxy compound having afunctional group capable of reacting with the epoxy group in saidpolyoxy compound.
 9. A cement composition comprising cement, water and acement additive comprising a crosslinked polymer in which, between mainchains having a water-soluble polymer structure of a weight averagemolecular weight from 500 to 100,000, a bond having as a structural unitat least one divalent group having the following formula (I) is formed##STR51## wherein R¹ and R² independently are selected from the groupconsisting of: ##STR52## with the proviso that R¹ is not required if R²is ##STR53## and wherein R and R' independently denote an alkyl group ofcarbon number of 1 to 5, said crosslinked polymer having a maximumviscosity of 100,000 cps in a 20% by weight aqueous solution ordispersion at a temperature of 20° C.,wherein said main chains compriseat least one member selected from the group consisting of ##STR54##wherein m is 0 or an integral number of 1 to 50; n is 0 or 1; M is atleast one member selected from the group consisting of a hydrogen atom,a monovalent, divalent or trivalent metal group, an ammonium group andan organic amine group; R⁵ and R⁶ independently denote an alkylene groupof carbon number 2 to 4; R⁷ denotes an alkylene group of carbon number 1to 5; with the proviso that when m is at least 2, a plurality of R⁵ Omay be the same or different and, when a plurality of R⁵ O are differentfrom one another, their arrangement may be regular or irregular; andwherein said main chains further comprise at least one functional groupselected from the group consisting of ##STR55## wherein p is an integralnumber of 1 to 10; q is 0 or an integral number of 1 to 100; r and sare, respectively, an integral number of 1 to 3; t and u are,respectively, an integral number of 1 to 100; A¹ is a straight chaindivalent or branched trivalent ring-opened group of an alkyleneimine of2 to 4 carbon atoms; R⁸ denotes CH₃ or C₂ H₅ ; R⁹ denotes H, CH₃, or C₂H₅ ; R¹⁰ denotes H or an alkyl group of carbon number 1 to 5; and X⊖denotes an anionic pair ion, with the proviso that, when p is at leasttwo, a plurality of A¹ groups may be the same or different and, when aplurality of A¹ are different from one another, their arrangement may beregular or irregular; and with the provision that when q is an integralnumber of from 1-100, the arrangement of A¹ and R⁵ O may be normal orreverse and may be regular or irregular, and wherein q is at least 2,when t is at least 2, and when u is at least 2, respectively, aplurality of R⁵ O may be the same or different and, when a plurality ofR⁵ O are different from one another, their arrangement may be regular orirregular, and wherein said crosslinked polymer is capable of forming awater-soluble polymer by cleavage of the divalent group in an alkalinemedium.
 10. A cement composition comprising cement, water and a cementadditive obtained from a method for producing a cement additive whichcomprises obtaining a crosslinked polymer by combining water-solublepolymers having a weight average molecular weight of 500 to 100,000 toone another by using a crosslinking agent which has a structural unit oris capable of forming at least one divalent group having the followingformula (I): ##STR56## wherein R¹ and R² independently are selected fromthe group consisting of: ##STR57## with the proviso that R¹ is notrequired if R² is ##STR58## and wherein R and R' independently denote analkyl group of carbon number of 1 to 5,said crosslinked polymer having amaximum viscosity of 100,000 cps in a 20% by weight aqueous solution ordispersion at a temperature of 20° C., wherein the water-soluble polymercomprises at least one member selected from the group consisting of##STR59## wherein m is 0 or an integral number of 1 to 50; n is 0 or 1;M is at least one member of the group consisting of a hydrogen atom, amonovalent, divalent or trivalent metal group, an ammonium group, and anorganic amine group, R⁵ and R⁶ independently denote an alkylene group ofcarbon number 2 to 4; R⁷ denotes an alkylene group of carbon number 1 to5, with the proviso that when m is at least 2, a plurality of R⁵ O maybe the same or different and, when a plurality of R⁵ O are differentfrom one another, their arrangement may be regular or irregular, andwherein the water-soluble polymer further comprises at least onefunctional group selected from the group consisting of ##STR60## whereinp is an integral number of 1 to 10, q is 0 or an integral number of 1 to100; r and s are, respectively, an integral number of 1 to 3; t and uare, respectively, an integral number of 1 to 100; A¹ is a straightchain divalent or branched trivalent ring-opened group of analkyleneimine of 2 to 4 carbon atoms; R⁸ denotes CH₃ or C₂ H₅ ; R⁹denotes H, CH₃, or C₂ H₅ ; R¹⁰ denotes H or an alkyl group of carbonnumber 1 to 5; and X.sup.⊖ denotes an anionic pair ion, with the provisothat, when p is at least two, a plurality of A¹ may be the same ordifferent and, when a plurality of A¹ are different from one another,their arrangement may be regular or irregular, with the proviso thatwhen q is an integral number of from 1 to 100, the arrangement of A¹ andR⁵ O may be normal or reverse and max be regular or irregular, with theproviso that when q is at least 2, when t is at least 2, and when u isat least 2, respectively, a plurality of R⁵ O may be the same ordifferent and when a plurality of R⁵ O are different from one another,their arrangement may be regular or irregular, and wherein saidcrosslinked polymer is capable of forming a water-soluble polymer bycleavage of the divalent group in an alkaline medium.
 11. A cementcomposition comprising cement, water and a cement additive obtained froma method for producing a cement additive which comprises obtaining acrosslinked polymer by combining water-soluble polymers having a weightaverage molecular weight of 500 to 100,000 to one another by using acrosslinking agent which has a structural unit or is capable of formingat least one divalent group having the following formula (I): ##STR61##wherein R¹ and R² independently are selected from the group consistingof: ##STR62## with the proviso that R¹ is not required if R² is##STR63## and wherein R and R' independently denote an alkyl group ofcarbon number of 1 to 5,said crosslinked polymer having a maximumviscosity of 100,000 cps in a 20% by weight aqueous solution ordispersion at a temperature of 20° C., wherein the water-soluble polymercomprises --COOM and ##STR64## wherein M is at least one member of thegroup consisting of a hydrogen atom, a monovalent, divalent or trivalentmetal group, an ammonium group, and an organic amine group, R⁵ denotesan alkylene group of carbon number 2 to 4; u is an integral number of 1to 100; and R¹⁰ denotes H or an alkyl group of carbon number 1 to 5,with the proviso that when u is at least 2, a plurality of R⁵ O may bethe same or different and when a plurality of R⁵ O are different fromone another, their arrangement may be regular or irregular, wherein thewater-soluble polymer is derived from a (poly)alkyleneglycolmono(meth)acrylate monomer (xiv) in an amount of 1 to 99.9% by weightand a (meth)acrylic monomer (i) in an amount of 99 to 0.1% by weightwherein the total (xiv) and (i) is 100% by weight and the crosslinkingagent has a functional group capable of reacting with at least onefunctional group selected from the group consisting of a carboxyl groupand a hydroxyl group being contained in the water-soluble polymer, andthe crosslinking agent and the water-soluble polymer are used in a molarratio range of 0.001 to 1.0 between a functional group of saidcrosslinking agent and a functional group of said water-soluble polymerwherein said monomer (i) has the structure: ##STR65## wherein M is atleast one member selected from the group consisting of a hydrogen atom,a monovalent, divalent or trivalent metal group, an ammonium group andan organic amine group; and R³ denotes H or CH₃ ; wherein said monomer(xiv) has the formula: ##STR66## wherein u is the integral number of 1to 100; with the proviso that, when u is at least 2, a plurality of R⁵ Omay be the same or different and, when a plurality of R⁵ O are differentfrom one another, their arrangement may be regular or irregular; andwherein said crosslinked polymer is capable of forming a water-solublepolymer by cleavage of the divalent group in an alkaline medium.
 12. Acement composition comprising cement, water and a cement additiveobtained from a method for producing a cement additive which comprisesobtaining a crosslinked polymer by a polymerization reaction of amonomer (e), which has at least two polymerizable double bonds and hasas a structural unit at least one divalent group having thebelow-described formula (I) between the double bonds, with a monomer(f), which has one polymerizable double bond capable of copolymerizingwith the double bond in (e) and is able to form a main chain structurecapable of leading to a water-soluble polymer of a weight averagemolecular weight of 500 to 100,000 ##STR67## wherein R¹ and R²independently are selected from the group consisting of: ##STR68## withthe proviso that R¹ is not required if R² is ##STR69## and wherein R andR' independently denote an alkyl group of carbon number of 1 to 5, saidcrosslinked polymer having a maximum viscosity of 100,000 cps in a 20%by weight aqueous solution or dispersion at a temperature of 20°C.,wherein the water-soluble polymer comprises at least one groupselected from the group consisting of ##STR70## wherein m is 0 or anintegral number of 1 to 50; n is 0 or 1; M is at least one memberselected from the group consisting of a hydrogen atom, a monovalent,divalent or trivalent metal group, an ammonium group and an organicamine group; R⁵ and R⁶ independently denote an alkylene group of 2 to 4carbon atoms; R⁷ denotes an alkylene group of 1 to 5 carbon atoms; withthe proviso that when m is at least 2, a plurality of R⁵ O may be thesame or different, and when a plurality of R⁵ O are different from oneanother, their arrangement may be regular or irregular, and wherein thewater-soluble polymer further comprises at least one group selected fromthe group consisting of ##STR71## wherein p is an integral number of 1to 10; q is 0 or an integral number of 1 to 100; r and s are,respectively, an integral number of 1 to 3; t and u are, respectively,an integral number of 1 to 100; A¹ is a straight chain divalent orbranched trivalent ring-opened group of an alkyleneimine of 2 to 4carbon atoms; R⁸ denotes CH₃ or C₂ H₅ ; R⁹ denotes H, CH₃ or C₂ H₅ ; R¹⁰denotes H or an alkyl group of carbon number 1 to 5; and X.sup.⊖ denotesan anionic pair ion, with the proviso that when p is at least two, aplurality of A¹ may be the same or different and, when a plurality of A¹are different from one another, their arrangement may be regular orirregular; and with the proviso that when q is an integral number offrom 1-100, the arrangement of A¹ and R⁵ O may be normal or reverse andmay be regular or irregular; and with the proviso that when q is atleast 2, when t is at least 2, and when u is at least 2 respectively, aplurality of R⁵ O may be the same or different and, when a plurality ofR⁵ O are different from one another, their arrangement may be regular orirregular; and wherein said crosslinked polymer is capable of forming awater-soluble polymer by cleavage of the divalent group in an alkalinemedium.
 13. A method for dispersing cement, comprising:dissolving thecement additive of claim 1 into water; and mixing a hydraulic materialwith said water in which said cement additive is dissolved.
 14. A methodfor dispersing cement, comprising:dissolving a cement additive, obtainedaccording to the method of claim 6, into water; and mixing a hydraulicmaterial with said water in which said cement additive is dissolved. 15.A method for dispersing cement, comprising:dissolving a cement additive,obtained according to the method of claim 7, into water; and mixing ahydraulic material with said water in which said cement additive isdissolved.
 16. A method for dispersing cement, comprising:dissolving acement additive, obtained according to the method of claim 8, intowater; and mixing a hydraulic material with said water in which saidcement additive is dissolved.
 17. A method for dispersing cement,comprising:dissolving a cement additive, obtained according to themethod of claim 2, into water; and mixing a hydraulic material with saidwater in which said cement additive is dissolved.
 18. A method fordispersing cement, comprising:dissolving a cement additive, obtainedaccording to the method of claim 3, into water; and mixing a hydraulicmaterial with said water in which said cement additive is dissolved. 19.A method for dispersing cement, comprising:dissolving a cement additive,obtained according to the method of claim 4, into water; and mixing ahydraulic material with said water in which said cement additive isdissolved.
 20. A method for dispersing cement, comprising:dissolving acement additive, obtained according to the method of claim 5, intowater; and mixing a hydraulic material with said water in which saidcement additive is dissolved.
 21. A method for dispersing cement,comprising mixing the following materials:a cement additive as describedin claim 1; water; and a hydraulic material.
 22. A method for dispersingcement, comprising mixing the following materials:a cement additiveobtained according to the method of claim 6; water; and a hydraulicmaterial.
 23. A method for dispersing cement, comprising mixing thefollowing materials:a cement additive obtained according to the methodof claim 7; water; and a hydraulic material.
 24. A method for dispersingcement, comprising mixing the following materials:a cement additiveobtained according to the method of claim 8; water; and a hydraulicmaterial.
 25. A method for dispersing cement, comprising mixing thefollowing materials:a cement additive obtained according to the methodof claim 2; water; and a hydraulic material.
 26. A method for dispersingcement, comprising mixing the following materials:a cement additiveobtained according to the method of claim 3; water; and a hydraulicmaterial.
 27. A method for dispersing cement, comprising mixing thefollowing materials:a cement additive obtained according to the methodof claim 4; water; and a hydraulic material.
 28. A method for dispersingcement, comprising mixing the following materials:a cement additiveobtained according to the method of claim 5; water; and a hydraulicmaterial.